diff --git a/.eslintignore b/.eslintignore
index e426d6c1d..cbe2fbd47 100644
--- a/.eslintignore
+++ b/.eslintignore
@@ -1,2 +1,3 @@
+node_modules
 coverage/
 bundlesize/
diff --git a/.eslintrc.js b/.eslintrc.js
index e7542dc4e..6b594419a 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -2,7 +2,13 @@ module.exports = {
   extends: ['@open-wc/eslint-config', 'eslint-config-prettier'].map(require.resolve),
   overrides: [
     {
-      files: ['**/test-suites/**/*.js', '**/test/**/*.js', '**/stories/**/*.js', '**/*.config.js'],
+      files: [
+        '**/test-suites/**/*.js',
+        '**/test/**/*.js',
+        '**/test-node/**/*.js',
+        '**/stories/**/*.js',
+        '**/*.config.js',
+      ],
       rules: {
         'no-console': 'off',
         'no-unused-expressions': 'off',
diff --git a/package.json b/package.json
index b339dd602..15aa301be 100644
--- a/package.json
+++ b/package.json
@@ -21,12 +21,14 @@
     "babel-eslint": "^8.2.6",
     "babel-polyfill": "^6.26.0",
     "bundlesize": "^0.17.1",
+    "chai": "^4.2.0",
     "eclint": "^2.8.1",
     "eslint": "^6.1.0",
     "husky": "^1.0.0",
     "lerna": "3.4.3",
     "lint-staged": "^8.0.0",
     "markdownlint-cli": "^0.17.0",
+    "mocha": "^7.1.1",
     "npm-run-all": "^4.1.5",
     "rimraf": "^2.6.3",
     "rollup": "^1.27.8",
@@ -38,7 +40,9 @@
     "start": "npm run storybook",
     "storybook": "start-storybook -p 9001",
     "storybook:build": "build-storybook",
-    "test": "karma start --coverage",
+    "test": "run-p test:browser test:node",
+    "test:browser": "karma start --coverage",
+    "test:node": "lerna run test:node",
     "test:watch": "karma start --auto-watch=true --single-run=false",
     "test:update-snapshots": "karma start --update-snapshots",
     "test:prune-snapshots": "karma start --prune-snapshots",
diff --git a/packages/remark-extend/README.md b/packages/remark-extend/README.md
new file mode 100644
index 000000000..0499b5538
--- /dev/null
+++ b/packages/remark-extend/README.md
@@ -0,0 +1,322 @@
+# remark-extend
+
+A plugin for remark to extend one markdown file with another.
+
+`remark-extend` is build to be integrated within the [unifiedjs](https://unifiedjs.com/) system.
+
+## Installation
+
+```bash
+npm i -D remark-extend
+```
+
+```js
+const unified = require('unified');
+const markdown = require('remark-parse');
+const mdStringify = require('remark-html');
+
+const { remarkExtend } = require('remark-extend');
+
+const sourceMd = '# Headline';
+const extendMd = 'extending instructions';
+
+const parser = unified()
+  .use(markdown)
+  .use(remarkExtend, { extendMd })
+  .use(mdStringify);
+const result = await parser.process(sourceMd);
+```
+
+## Extending Instructions
+
+### Selection
+
+For modifications you will need to provide a starting node.
+In order to get this node css like selectors from [unist-util-select](https://github.com/syntax-tree/unist-util-select#support) are supported.
+
+Some examples are:
+
+- `:root` for the top of the markdown file
+- `:scope:last-child` for the end of the markdown file
+- `heading:has([value=Red])` first heading with a text value of Red (e.g. ### Red)
+- `heading[depth=2]` first third level heading (e.g. ## Something)
+
+### Markdown AST
+
+All adjustments to the markdown file happen via the markdown AST (Abstract Syntax Tree).
+
+You can explore it via the [ASTExplorer](https://astexplorer.net/).
+
+```md
+### Red
+
+red is the fire
+```
+
+Resulting AST.
+
+```json
+{
+  "type": "root",
+  "children": [
+    {
+      "type": "heading",
+      "depth": 3,
+      "children": [
+        {
+          "type": "text",
+          "value": "Red"
+        }
+      ]
+    },
+    {
+      "type": "paragraph",
+      "children": [
+        {
+          "type": "text",
+          "value": "red is the fire"
+        }
+      ]
+    }
+  ]
+}
+```
+
+---
+
+### Replacement
+
+Does adjustments from a start point downwards.
+The provided function does get called for every node from the starting point (including the starting point).
+
+#### Replacement Input File
+
+```md
+### Red
+
+red is the fire
+```
+
+#### Replacement Extending File
+
+Goal is to replace all red with green.
+
+````md
+```js ::replaceFrom(':root')
+module.exports.replaceSection = node => {
+  if (node.value) {
+    node.value = node.value.replace(/red/g, 'green').replace(/Red/g, 'Green');
+  }
+  return node;
+};
+```
+````
+
+This function gets called with these nodes in order.
+
+1. root
+2. heading
+3. text
+4. paragraph
+5. text
+
+#### Replacement Result
+
+```md
+### Green
+
+green is the fire
+```
+
+### Replacement Range
+
+Whenever a section or part of the original markdown needs to be adjusted.
+The function does get every node from the starting point (including the starting point) till the end point (excluding the end point).
+
+#### Replacement Range Input File
+
+```md
+### Red <-- starting point (including)
+
+red is the fire
+
+### More Red <-- end point (excluding)
+
+the sun can get red
+```
+
+#### Replacement Range Extending File
+
+````md
+```js ::replaceBetween('heading:has([value=Red])', 'heading:has([value=More Red])')
+module.exports.replaceSection = node => {
+  if (node.value) {
+    node.value = node.value.replace(/red/g, 'green').replace(/Red/g, 'Green');
+  }
+  return node;
+};
+```
+````
+
+#### Replacement Range Result
+
+```md
+### Green <-- starting point (including)
+
+green is the fire
+
+### More Red <-- end point (excluding)
+
+the sun can get red
+```
+
+---
+
+### Add More Markdown Content After
+
+If additional markdown content should be inserted after at a specific location.
+
+#### Add After Input File
+
+```md
+### Red
+
+red is the fire
+```
+
+#### Add After Extending File
+
+````md
+```
+::addMdAfter('heading:has([value=Red])')
+```
+
+the ocean is blue
+````
+
+#### Add After Result
+
+```md
+### Red
+
+the ocean is blue
+red is the fire
+```
+
+More example use cases:
+
+- Add more markdown at the top `::addMdAfter(':root')`
+- Add more markdown at the bottom `::addMdAfter(':scope:last-child')`
+
+### Add More Markdown Content Before
+
+If additional markdown content should be inserted before at a specific location.
+Useful for adding disclaimers above a headline.
+
+#### Add Before Input File
+
+```md
+### Red
+
+red is the fire
+
+### Green <-- staring point
+```
+
+#### Add Before Extending File
+
+````md
+```
+::addMdBefore('heading:has([value=Red])')
+```
+
+the ocean is blue
+````
+
+#### Add Before Result
+
+```md
+### Red
+
+red is the fire
+
+the ocean is blue
+
+### Green <-- staring point
+```
+
+More example use cases:
+
+- Add something at the end of a "section": `::addMdBefore('heading:has([value=Red]) ~ heading[depth=3]')`
+  It works by selecting the headline of your section and add before the next sibling headline with the same depth.
+
+---
+
+### Removal
+
+Does adjustments from a start point downwards.
+The provided function does get called for every node from the starting point (including the starting point).
+
+#### Removal Input File
+
+```md
+### Red
+
+red is the fire
+
+### More Red // <-- start
+
+the sun can get red
+```
+
+#### Removal Extending File
+
+Goal is to remove everything after `### More Red`
+
+````md
+```
+::removeFrom('heading:has([value=More Red])')
+```
+````
+
+#### Removal Result
+
+```md
+### Red
+
+red is the fire
+```
+
+### Removal Range
+
+Whenever a section or part of the original markdown needs to be removed.
+
+#### Removal Range Input File
+
+```md
+### Red <-- starting point (including)
+
+red is the fire
+
+### More Red <-- end point (excluding)
+
+the sun can get red
+```
+
+#### Removal Range Extending File
+
+Starting from `### Red` until the next headline with depth of 3.
+
+````md
+```
+::removeBetween('heading:has([value=Red])', 'heading:has([value=Red]) ~ heading[depth=3]')
+```
+````
+
+#### Removal Range Result
+
+```md
+### More Red <-- end point (excluding)
+
+the sun can get red
+```
diff --git a/packages/remark-extend/package.json b/packages/remark-extend/package.json
new file mode 100644
index 000000000..8a6f91fe2
--- /dev/null
+++ b/packages/remark-extend/package.json
@@ -0,0 +1,43 @@
+{
+  "name": "remark-extend",
+  "version": "0.0.0",
+  "description": "A plugin for remark that allows to extend a md file with another md file",
+  "author": "ing-bank",
+  "homepage": "https://github.com/ing-bank/lion/",
+  "license": "MIT",
+  "publishConfig": {
+    "access": "public"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/ing-bank/lion.git",
+    "directory": "packages/remark-extend"
+  },
+  "scripts": {
+    "prepublishOnly": "../../scripts/npm-prepublish.js",
+    "test": "npm run test:node",
+    "test:node": "mocha test-node",
+    "test:watch": "mocha test-node --watch"
+  },
+  "keywords": [
+    "remark"
+  ],
+  "main": "index.js",
+  "files": [
+    "docs",
+    "src",
+    "stories",
+    "test",
+    "*.js"
+  ],
+  "dependencies": {
+    "remark-parse": "^8.0.0",
+    "unified": "^9.0.0",
+    "unist-util-is": "^4.0.2",
+    "unist-util-select": "^3.0.1",
+    "unist-util-visit": "^2.0.2"
+  },
+  "devDependencies": {
+    "remark-html": "^11.0.1"
+  }
+}
diff --git a/packages/remark-extend/src/remarkExtend.js b/packages/remark-extend/src/remarkExtend.js
new file mode 100644
index 000000000..7b1f133d0
--- /dev/null
+++ b/packages/remark-extend/src/remarkExtend.js
@@ -0,0 +1,305 @@
+// unified works my modifying the original passed node
+/* eslint-disable no-param-reassign */
+const visit = require('unist-util-visit');
+const { select } = require('unist-util-select');
+const unified = require('unified');
+const markdown = require('remark-parse');
+const is = require('unist-util-is');
+
+function addTask(file, newAction) {
+  if (!file.data.remarkExtend) {
+    file.data.remarkExtend = [];
+  }
+  file.data.remarkExtend.push(newAction);
+}
+
+function findReplacementTasks(tree, file) {
+  visit(tree, 'code', node => {
+    if (node.lang === 'js' && node.meta && node.meta.startsWith('::replaceFrom')) {
+      const startSelector = node.meta.substring(
+        node.meta.indexOf("('") + 2,
+        node.meta.indexOf("')"),
+      );
+      addTask(file, {
+        action: 'replaceFrom',
+        startSelector,
+        jsCode: node.value,
+      });
+    }
+    if (node.lang === 'js' && node.meta && node.meta.startsWith('::replaceBetween')) {
+      const startSelector = node.meta.substring(
+        node.meta.indexOf("('") + 2,
+        node.meta.indexOf("',"),
+      );
+      const endSelector = node.meta
+        .substring(node.meta.indexOf("',") + 4, node.meta.indexOf("')"))
+        .trim();
+      addTask(file, {
+        action: 'replaceBetween',
+        startSelector,
+        endSelector,
+        jsCode: node.value,
+      });
+    }
+  });
+}
+
+function shouldFinishGathering(node) {
+  if (node.type === 'code' && node.lang === 'js' && node.meta && node.meta.startsWith('::')) {
+    return true;
+  }
+  if (node.value && node.value.startsWith('::')) {
+    return true;
+  }
+  return false;
+}
+
+function findMdAdditionTasks(tree, file) {
+  let addNodes = [];
+  let gathering = false;
+  let startSelector;
+  let action = '';
+  visit(tree, (node, index, parent) => {
+    if (gathering === true && shouldFinishGathering(node)) {
+      gathering = false;
+      addTask(file, {
+        action,
+        startSelector,
+        addNodes,
+      });
+      addNodes = [];
+    }
+
+    if (gathering === true) {
+      if (parent.type === 'root') {
+        addNodes.push(node);
+      }
+    }
+
+    if (node.type === 'code' && node.value && node.value.startsWith('::addMdAfter')) {
+      startSelector = node.value.substring(node.value.indexOf("('") + 2, node.value.indexOf("')"));
+      gathering = true;
+      action = 'addMdAfter';
+    }
+    if (node.type === 'code' && node.value && node.value.startsWith('::addMdBefore')) {
+      startSelector = node.value.substring(node.value.indexOf("('") + 2, node.value.indexOf("')"));
+      gathering = true;
+      action = 'addMdBefore';
+    }
+  });
+
+  if (gathering === true) {
+    addTask(file, {
+      action,
+      startSelector,
+      addNodes,
+    });
+  }
+}
+
+function findRemoveTasks(tree, file) {
+  visit(tree, 'code', node => {
+    if (node.value && node.value.startsWith('::removeFrom')) {
+      const startSelector = node.value.substring(
+        node.value.indexOf("('") + 2,
+        node.value.indexOf("')"),
+      );
+      addTask(file, {
+        action: 'removeFrom',
+        startSelector,
+      });
+    }
+    if (node.value && node.value.startsWith('::removeBetween')) {
+      const startSelector = node.value.substring(
+        node.value.indexOf("('") + 2,
+        node.value.indexOf("',"),
+      );
+      const endSelector = node.value
+        .substring(node.value.indexOf("',") + 4, node.value.indexOf("')"))
+        .trim();
+      addTask(file, {
+        action: 'removeBetween',
+        startSelector,
+        endSelector,
+      });
+    }
+  });
+}
+
+function findExtendTasks() {
+  return (tree, file) => {
+    findReplacementTasks(tree, file);
+    findMdAdditionTasks(tree, file);
+    findRemoveTasks(tree, file);
+  };
+}
+
+/**
+ * Allows to execute an actual node module code block.
+ * Supports imports (via require) within those code blocks.
+ *
+ * @example
+ *   const virtualMod = requireFromString('module.export = { a: "a value", fn: () => {} }');
+ *   console.log(virtualMod.a); // a value
+ *   // execute function
+ *   virtualMod.fn();
+ *
+ * @param {*} src
+ * @param {*} filename
+ */
+function requireFromString(src, filename = 'tmp.js') {
+  const m = new module.constructor();
+  m.paths = module.paths;
+  m._compile(src, filename);
+  return m.exports;
+}
+
+function handleAdditions(tree, action, startIsNode, addNodes) {
+  visit(tree, (node, index, parent) => {
+    if (is(node, startIsNode)) {
+      if (action === 'addMdAfter') {
+        if (node.type === 'root') {
+          node.children.splice(0, 0, ...addNodes);
+        } else {
+          parent.children.splice(index + 1, 0, ...addNodes);
+        }
+      }
+      if (action === 'addMdBefore') {
+        if (node.remarkExtendedProcessed === undefined) {
+          // preventing infinite loops as adding a node before means we visit the target node again and insert again
+          node.remarkExtendedProcessed = true;
+          if (node.type === 'root') {
+            node.children.splice(0, 0, ...addNodes);
+          } else {
+            parent.children.splice(index, 0, ...addNodes);
+          }
+        }
+      }
+    }
+  });
+}
+
+function handleReplacements(tree, action, startIsNode, endIsNode, jsCode) {
+  let doReplacements = false;
+  let resetAtEnd = false;
+  let userFunction;
+  if (action === 'replaceFrom' || action === 'replaceBetween') {
+    const virtualMod = requireFromString(jsCode);
+    const keys = Object.keys(virtualMod);
+    userFunction = virtualMod[keys[0]];
+  }
+  visit(tree, (node, index, parent) => {
+    if (is(node, startIsNode)) {
+      doReplacements = true;
+    }
+    if (action === 'replaceBetween' && is(node, endIsNode)) {
+      resetAtEnd = true;
+    }
+    if (doReplacements) {
+      node = userFunction(node, { index, parent, tree });
+    }
+    if (resetAtEnd === true) {
+      resetAtEnd = false;
+      doReplacements = false;
+    }
+  });
+}
+
+/**
+ * Needs 2 loops as
+ * - First to mark nodes for removal
+ * - Do actual removal in revers order (to not effect the index of the loop)
+ *
+ * @param {*} tree
+ * @param {*} action
+ * @param {*} startIsNode
+ * @param {*} endIsNode
+ */
+function handleRemovals(tree, action, startIsNode, endIsNode) {
+  let removeIt = false;
+  visit(tree, (node, index, parent) => {
+    if (is(node, startIsNode)) {
+      removeIt = true;
+    }
+    if (action === 'removeBetween' && is(node, endIsNode)) {
+      removeIt = false;
+    }
+    if (removeIt && parent.type === 'root') {
+      // only mark for removal
+      // removing directly messes with the index which prevents further removals down the line
+      parent.children[index].__remarkExtendRemove = true;
+    }
+  });
+  visit(
+    tree,
+    (node, index, parent) => {
+      if (node.__remarkExtendRemove) {
+        parent.children.splice(index, 1);
+      }
+    },
+    true,
+  );
+}
+
+// unified expect direct
+// eslint-disable-next-line consistent-return
+function remarkExtend(options) {
+  if (options.extendMd) {
+    const parser = unified()
+      .use(markdown)
+      .use(findExtendTasks)
+      .use(function plugin() {
+        this.Compiler = () => '';
+      });
+
+    const changes = parser.processSync(options.extendMd);
+
+    const extensionTasks = changes.data.remarkExtend;
+
+    if (!extensionTasks) {
+      return tree => tree;
+    }
+
+    return tree => {
+      for (const extensionTask of extensionTasks) {
+        const { action, startSelector, endSelector, jsCode, addNodes } = extensionTask;
+        const start = select(extensionTask.startSelector, tree);
+        if (!start) {
+          throw new Error(`The start selector "${startSelector}" could not find a matching node.`);
+        }
+        const startIsNode = { ...start };
+        delete startIsNode.children; // unified is comparison does not support children
+
+        let endIsNode;
+        if (action === 'replaceBetween' || action === 'removeBetween') {
+          const end = select(endSelector, tree);
+          if (!end) {
+            throw new Error(`The end selector "${endSelector}" could not find a matching node.`);
+          }
+          endIsNode = { ...end };
+          delete endIsNode.children; // unified is comparison does not support children
+        }
+
+        switch (action) {
+          case 'addMdAfter':
+          case 'addMdBefore':
+            handleAdditions(tree, action, startIsNode, addNodes);
+            break;
+          case 'replaceFrom':
+          case 'replaceBetween':
+            handleReplacements(tree, action, startIsNode, endIsNode, jsCode);
+            break;
+          case 'removeFrom':
+          case 'removeBetween':
+            handleRemovals(tree, action, startIsNode, endIsNode);
+            break;
+          /* no default */
+        }
+      }
+    };
+  }
+}
+
+module.exports = {
+  remarkExtend,
+};
diff --git a/packages/remark-extend/test-node/remark-extend.test.js b/packages/remark-extend/test-node/remark-extend.test.js
new file mode 100644
index 000000000..a4bf19035
--- /dev/null
+++ b/packages/remark-extend/test-node/remark-extend.test.js
@@ -0,0 +1,628 @@
+const { expect } = require('chai');
+
+const unified = require('unified');
+const markdown = require('remark-parse');
+const mdStringify = require('remark-html');
+
+const { remarkExtend } = require('../src/remarkExtend.js');
+
+async function expectThrowsAsync(method, errorMessage) {
+  let error = null;
+  try {
+    await method();
+  } catch (err) {
+    error = err;
+  }
+  expect(error).to.be.an('Error', 'No error was thrown');
+  if (errorMessage) {
+    expect(error.message).to.equal(errorMessage);
+  }
+}
+
+describe('remarkExtend', () => {
+  it('does no modifications if no action is found', async () => {
+    const input = [
+      '### Red',
+      '',
+      'red is the fire',
+      '',
+      '#### More Red',
+      '',
+      'the sun can get red',
+    ].join('\n');
+    const extendMd = '';
+    const output = [
+      '<h3>Red</h3>',
+      '<p>red is the fire</p>',
+      '<h4>More Red</h4>',
+      '<p>the sun can get red</p>',
+      '',
+    ].join('\n');
+
+    const parser = unified()
+      //
+      .use(markdown)
+      .use(remarkExtend, { extendMd })
+      .use(mdStringify);
+    const result = await parser.process(input);
+
+    expect(result.contents).to.equal(output);
+  });
+
+  it('can do replacements on the full file', async () => {
+    const input = [
+      '### Red', // <-- start
+      '',
+      'red is the fire',
+      '',
+      '#### More Red',
+      '',
+      'the sun can get red',
+    ].join('\n');
+    const extendMd = [
+      //
+      "```js ::replaceFrom(':root')",
+      'module.exports.replaceSection = (node) => {',
+      '  if (node.value) {',
+      "     node.value = node.value.replace(/red/g, 'green').replace(/Red/g, 'Green');",
+      '  }',
+      '  return node;',
+      '};',
+      '```',
+    ].join('\n');
+    const output = [
+      '<h3>Green</h3>', // <-- start
+      '<p>green is the fire</p>',
+      '<h4>More Green</h4>',
+      '<p>the sun can get green</p>',
+      '',
+    ].join('\n');
+
+    const parser = unified()
+      //
+      .use(markdown)
+      .use(remarkExtend, { extendMd })
+      .use(mdStringify);
+    const result = await parser.process(input);
+
+    expect(result.contents).to.equal(output);
+  });
+
+  it('does replacements in order of extendMd', async () => {
+    const input = [
+      '### Red', // <-- start
+      '',
+      'red is the fire',
+    ].join('\n');
+    const extendMd = [
+      "```js ::replaceFrom(':root')",
+      'module.exports.replaceSection = (node) => {',
+      '  if (node.value) {',
+      "     node.value = node.value.replace(/red/g, 'green').replace(/Red/g, 'Green');",
+      '  }',
+      '  return node;',
+      '};',
+      '```',
+      "```js ::replaceFrom(':root')",
+      'module.exports.replaceSection = (node) => {',
+      '  if (node.value) {',
+      "     node.value = node.value.replace(/green/g, 'yellow').replace(/Green/g, 'Yellow');",
+      '  }',
+      '  return node;',
+      '};',
+      '```',
+    ].join('\n');
+    const output = [
+      '<h3>Yellow</h3>', // <-- start
+      '<p>yellow is the fire</p>',
+      '',
+    ].join('\n');
+
+    const parser = unified()
+      //
+      .use(markdown)
+      .use(remarkExtend, { extendMd })
+      .use(mdStringify);
+    const result = await parser.process(input);
+
+    expect(result.contents).to.equal(output);
+  });
+
+  it('can replace from a starting point downward', async () => {
+    const input = [
+      '### Red',
+      '',
+      'red is the fire',
+      '',
+      '### More Red', // <-- start
+      '',
+      'the sun can get red',
+    ].join('\n');
+    const extendMd = [
+      "```js ::replaceFrom('heading[depth=3]:has([value=More Red])')",
+      'module.exports.replaceSection = (node) => {',
+      '  if (node.value) {',
+      "     node.value = node.value.replace(/red/g, 'green').replace(/Red/g, 'Green');",
+      '  }',
+      '  return node;',
+      '};',
+      '```',
+    ].join('\n');
+    const output = [
+      '<h3>Red</h3>',
+      '<p>red is the fire</p>',
+      '<h3>More Green</h3>', // <-- start
+      '<p>the sun can get green</p>',
+      '',
+    ].join('\n');
+
+    const parser = unified()
+      //
+      .use(markdown)
+      .use(remarkExtend, { extendMd })
+      .use(mdStringify);
+    const result = await parser.process(input);
+
+    expect(result.contents).to.equal(output);
+  });
+
+  it('throws if a start selector is not found', async () => {
+    const input = [
+      //
+      '### Red',
+    ].join('\n');
+    const extendMd = [
+      "```js ::replaceFrom('heading:has([value=More Red])')",
+      'module.exports.replaceSection = (node) => {}',
+      '```',
+    ].join('\n');
+
+    const parser = unified()
+      //
+      .use(markdown)
+      .use(remarkExtend, { extendMd })
+      .use(mdStringify);
+
+    await expectThrowsAsync(
+      () => parser.process(input),
+      'The start selector "heading:has([value=More Red])" could not find a matching node.',
+    );
+  });
+
+  it('can replace within a range (start point included, endpoint not)', async () => {
+    const input = [
+      '### Red',
+      '',
+      'red is the fire',
+      '',
+      'red is the cross', // <-- start
+      '',
+      'red is the flag',
+      '',
+      '#### More Red',
+      '',
+      'the sun can get red',
+    ].join('\n');
+    const extendMd = [
+      "```js ::replaceBetween('heading:has([value=Red]) ~ paragraph:nth-of-type(2)', 'heading:has([value=More Red])')",
+      'module.exports.replaceSection = (node) => {',
+      '  if (node.value) {',
+      "     node.value = node.value.replace(/red/g, 'green').replace(/Red/g, 'Green');",
+      '  }',
+      '  return node',
+      '};',
+    ].join('\n');
+    const output = [
+      '<h3>Red</h3>',
+      '<p>red is the fire</p>',
+      '<p>green is the cross</p>', // <-- start
+      '<p>green is the flag</p>',
+      '<h4>More Red</h4>', // <-- end
+      '<p>the sun can get red</p>',
+      '',
+    ].join('\n');
+    const parser = unified()
+      //
+      .use(markdown)
+      .use(remarkExtend, { extendMd })
+      .use(mdStringify);
+    const result = await parser.process(input);
+
+    expect(result.contents).to.equal(output);
+  });
+
+  it('throws if a end selector is not found', async () => {
+    const input = [
+      //
+      '### Red',
+    ].join('\n');
+    const extendMd = [
+      "```js ::replaceBetween('heading:has([value=Red])', 'heading:has([value=Red2])')",
+      'module.exports.replaceSection = (node) => {}',
+      '```',
+    ].join('\n');
+
+    const parser = unified()
+      .use(markdown)
+      .use(remarkExtend, { extendMd })
+      .use(mdStringify);
+
+    await expectThrowsAsync(
+      () => parser.process(input),
+      'The end selector "heading:has([value=Red2])" could not find a matching node.',
+    );
+  });
+
+  it('replaces a single node if replacing between the start and end of the same node', async () => {
+    const input = [
+      //
+      '### Red',
+      'red',
+      '### Red',
+    ].join('\n');
+    const extendMd = [
+      "```js ::replaceBetween('heading:has([value=Red]) > text', 'heading:has([value=Red]) > text')",
+      'module.exports.replaceSection = (node) => {',
+      '  if (node.value) {',
+      "     node.value = node.value.replace(/red/g, 'green').replace(/Red/g, 'Green');",
+      '  }',
+      '  return node',
+      '};',
+      '```',
+    ].join('\n');
+    const output = [
+      '<h3>Green</h3>', // text node "Green" == start == end
+      '<p>red</p>',
+      '<h3>Red</h3>',
+      '',
+    ].join('\n');
+
+    const parser = unified()
+      //
+      .use(markdown)
+      .use(remarkExtend, { extendMd })
+      .use(mdStringify);
+
+    const result = await parser.process(input);
+
+    expect(result.contents).to.equal(output);
+  });
+
+  it('can put something after via "::addMdAfter"', async () => {
+    const input = [
+      //
+      '### Red',
+      '',
+      'red is the fire',
+    ].join('\n');
+    const extendMd = [
+      '```',
+      "::addMdAfter('heading:has([value=Red])')",
+      '```',
+      '',
+      'the ocean is blue',
+    ].join('\n');
+    const output = [
+      //
+      '<h3>Red</h3>',
+      '<p>the ocean is blue</p>',
+      '<p>red is the fire</p>',
+      '',
+    ].join('\n');
+    const parser = unified()
+      //
+      .use(markdown)
+      .use(remarkExtend, { extendMd })
+      .use(mdStringify);
+    const result = await parser.process(input);
+
+    expect(result.contents).to.equal(output);
+  });
+
+  it('adding stops at the next ::[action]', async () => {
+    const input = [
+      //
+      '### Red',
+      '',
+      'red is the fire',
+      '',
+      '### More Red',
+    ].join('\n');
+    const extendMd = [
+      '```',
+      "::addMdAfter('heading:has([value=Red])')",
+      '```',
+      '',
+      'the ocean is blue',
+      '',
+      '```',
+      "::addMdAfter('heading:has([value=More Red])')",
+      '```',
+      '',
+      'as in the sun is the ultimate red',
+      '',
+      "```js ::replaceBetween('heading:has([value=Red])', 'heading:has([value=Red])')",
+      'module.exports.replaceSection = (node) => {}',
+      '```',
+      'content not part of an add so it gets ignored',
+    ].join('\n');
+    const output = [
+      //
+      '<h3>Red</h3>',
+      '<p>the ocean is blue</p>',
+      '<p>red is the fire</p>',
+      '<h3>More Red</h3>',
+      '<p>as in the sun is the ultimate red</p>',
+      '',
+    ].join('\n');
+    const parser = unified()
+      //
+      .use(markdown)
+      .use(remarkExtend, { extendMd })
+      .use(mdStringify);
+    const result = await parser.process(input);
+
+    expect(result.contents).to.equal(output);
+  });
+
+  it('will throw if trying to immediate run replacements of added content', async () => {
+    const input = [
+      //
+      '### Red',
+      '',
+    ].join('\n');
+    const extendMd = [
+      '```',
+      "::addMdAfter('heading:has([value=Red])')",
+      '```',
+      '',
+      '## Blue',
+      '',
+      "```js ::replaceFrom('heading:has([value=Blue])')",
+      'module.exports.replaceSection = (node) => {',
+      '  if (node.value) {',
+      "     node.value = node.value.replace(/Blue/g, 'Yellow');",
+      '  }',
+      '  return node',
+      '}',
+      '```',
+    ].join('\n');
+    const parser = unified()
+      //
+      .use(markdown)
+      .use(remarkExtend, { extendMd })
+      .use(mdStringify);
+
+    await expectThrowsAsync(
+      () => parser.process(input),
+      'The start selector "heading:has([value=Blue])" could not find a matching node.',
+    );
+  });
+
+  it(`can put something right at the top via "::addMdAfter(':root')"`, async () => {
+    const input = [
+      //
+      '### Red',
+    ].join('\n');
+    const extendMd = [
+      //
+      '```',
+      "::addMdAfter(':root')",
+      '```',
+      '',
+      '# New Headline',
+    ].join('\n');
+    const output = [
+      //
+      '<h1>New Headline</h1>',
+      '<h3>Red</h3>',
+      '',
+    ].join('\n');
+    const parser = unified()
+      //
+      .use(markdown)
+      .use(remarkExtend, { extendMd })
+      .use(mdStringify);
+    const result = await parser.process(input);
+
+    expect(result.contents).to.equal(output);
+  });
+
+  it(`can put something right at the bottom via "::addMdAfter(':scope:last-child')"`, async () => {
+    const input = [
+      //
+      '### Red',
+      '',
+      'red is the fire',
+    ].join('\n');
+    const extendMd = [
+      //
+      '```',
+      "::addMdAfter(':scope:last-child')",
+      '```',
+      '',
+      'extra text',
+    ].join('\n');
+    const output = [
+      //
+      '<h3>Red</h3>',
+      '<p>red is the fire</p>',
+      '<p>extra text</p>',
+      '',
+    ].join('\n');
+    const parser = unified()
+      //
+      .use(markdown)
+      .use(remarkExtend, { extendMd })
+      .use(mdStringify);
+    const result = await parser.process(input);
+
+    expect(result.contents).to.equal(output);
+  });
+
+  it('can put something before via "::addMdBefore"', async () => {
+    const input = [
+      //
+      '### Red',
+      '',
+      'red is the fire',
+      '',
+      '### Blue',
+    ].join('\n');
+    const extendMd = [
+      '```',
+      "::addMdBefore('heading:has([value=Blue])')",
+      '```',
+      '',
+      'the ocean is blue',
+    ].join('\n');
+    const output = [
+      //
+      '<h3>Red</h3>',
+      '<p>red is the fire</p>',
+      '<p>the ocean is blue</p>',
+      '<h3>Blue</h3>',
+      '',
+    ].join('\n');
+    const parser = unified()
+      //
+      .use(markdown)
+      .use(remarkExtend, { extendMd })
+      .use(mdStringify);
+    const result = await parser.process(input);
+
+    expect(result.contents).to.equal(output);
+  });
+
+  it(`can put something at the end of a "section" via "::addMdBefore('heading:has([value=Red]) ~ heading[depth=3]')"`, async () => {
+    const input = [
+      //
+      '### Red',
+      '',
+      'red is the fire',
+      '',
+      '### Blue',
+    ].join('\n');
+    const extendMd = [
+      '```',
+      "::addMdBefore('heading:has([value=Red]) ~ heading[depth=3]')",
+      '```',
+      '',
+      'the sun will be red',
+    ].join('\n');
+    const output = [
+      //
+      '<h3>Red</h3>',
+      '<p>red is the fire</p>',
+      '<p>the sun will be red</p>',
+      '<h3>Blue</h3>',
+      '',
+    ].join('\n');
+    const parser = unified()
+      //
+      .use(markdown)
+      .use(remarkExtend, { extendMd })
+      .use(mdStringify);
+    const result = await parser.process(input);
+
+    expect(result.contents).to.equal(output);
+  });
+
+  it(`can put something at the top of the file via '::addMdBefore(":root")'`, async () => {
+    const input = [
+      //
+      '### Red',
+      '',
+      'red is the fire',
+      '',
+      '### Blue',
+    ].join('\n');
+    const extendMd = [
+      //
+      '```',
+      "::addMdBefore(':root')",
+      '```',
+      '',
+      'the ocean is blue',
+    ].join('\n');
+    const output = [
+      //
+      '<p>the ocean is blue</p>',
+      '<h3>Red</h3>',
+      '<p>red is the fire</p>',
+      '<h3>Blue</h3>',
+      '',
+    ].join('\n');
+    const parser = unified()
+      //
+      .use(markdown)
+      .use(remarkExtend, { extendMd })
+      .use(mdStringify);
+    const result = await parser.process(input);
+
+    expect(result.contents).to.equal(output);
+  });
+
+  it('can remove from a starting point downward', async () => {
+    const input = [
+      '### Red',
+      '',
+      'red is the fire',
+      '',
+      '### More Red', // <-- start
+      '',
+      'the sun can get red',
+    ].join('\n');
+    const extendMd = [
+      //
+      '```',
+      "::removeFrom('heading:has([value=More Red])')",
+      '```',
+    ].join('\n');
+    const output = [
+      //
+      '<h3>Red</h3>',
+      '<p>red is the fire</p>',
+      '',
+    ].join('\n');
+
+    const parser = unified()
+      //
+      .use(markdown)
+      .use(remarkExtend, { extendMd })
+      .use(mdStringify);
+    const result = await parser.process(input);
+
+    expect(result.contents).to.equal(output);
+  });
+
+  it('can remove a range (start point included, endpoint not)', async () => {
+    const input = [
+      '### Red', // <-- start
+      '',
+      'red is the fire',
+      '',
+      '### More Red', // <-- end
+      '',
+      'the sun can get red',
+    ].join('\n');
+    const extendMd = [
+      '```',
+      `::removeBetween('heading:has([value=Red])', 'heading:has([value=Red]) ~ heading[depth=3]')`,
+      '```',
+    ].join('\n');
+    const output = [
+      '<h3>More Red</h3>', // <-- end
+      '<p>the sun can get red</p>',
+      '',
+    ].join('\n');
+    const parser = unified()
+      //
+      .use(markdown)
+      .use(remarkExtend, { extendMd })
+      .use(mdStringify);
+    const result = await parser.process(input);
+
+    expect(result.contents).to.equal(output);
+  });
+});
diff --git a/yarn.lock b/yarn.lock
index 31186de7e..292e80973 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3933,6 +3933,11 @@ body-parser@^1.16.1:
     raw-body "2.4.0"
     type-is "~1.6.17"
 
+boolbase@~1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/boolbase/-/boolbase-1.0.0.tgz#68dff5fbe60c51eb37725ea9e3ed310dcc1e776e"
+  integrity sha1-aN/1++YMUes3cl6p4+0xDcwed24=
+
 brace-expansion@^1.0.0, brace-expansion@^1.1.7:
   version "1.1.11"
   resolved "https://registry.yarnpkg.com/brace-expansion/-/brace-expansion-1.1.11.tgz#3c7fcbf529d87226f3d2f52b966ff5271eb441dd"
@@ -4355,7 +4360,7 @@ caseless@~0.12.0:
   resolved "https://registry.yarnpkg.com/caseless/-/caseless-0.12.0.tgz#1b681c21ff84033c826543090689420d187151dc"
   integrity sha1-G2gcIf+EAzyCZUMJBolCDRhxUdw=
 
-ccount@^1.0.3:
+ccount@^1.0.0, ccount@^1.0.3:
   version "1.0.5"
   resolved "https://registry.yarnpkg.com/ccount/-/ccount-1.0.5.tgz#ac82a944905a65ce204eb03023157edf29425c17"
   integrity sha512-MOli1W+nfbPLlKEhInaxhRdp7KVLFxLN5ykwzHgLsLI3H3gs5jjFAK4Eoj3OzzcxCtumDaI8onoVDeQyWaNTkw==
@@ -4433,6 +4438,11 @@ change-emitter@^0.1.2:
   resolved "https://registry.yarnpkg.com/change-emitter/-/change-emitter-0.1.6.tgz#e8b2fe3d7f1ab7d69a32199aff91ea6931409515"
   integrity sha1-6LL+PX8at9aaMhma/5HqaTFAlRU=
 
+character-entities-html4@^1.0.0:
+  version "1.1.4"
+  resolved "https://registry.yarnpkg.com/character-entities-html4/-/character-entities-html4-1.1.4.tgz#0e64b0a3753ddbf1fdc044c5fd01d0199a02e125"
+  integrity sha512-HRcDxZuZqMx3/a+qrzxdBKBPUpxWEq9xw2OPZ3a/174ihfrQKVsFhqtthBInFy1zZ9GgZyFXOatNujm8M+El3g==
+
 character-entities-legacy@^1.0.0:
   version "1.1.4"
   resolved "https://registry.yarnpkg.com/character-entities-legacy/-/character-entities-legacy-1.1.4.tgz#94bc1845dce70a5bb9d2ecc748725661293d8fc1"
@@ -4477,6 +4487,21 @@ checkstyle-formatter@^1.1.0:
   dependencies:
     xml-escape "^1.0.0"
 
+chokidar@3.3.0:
+  version "3.3.0"
+  resolved "https://registry.yarnpkg.com/chokidar/-/chokidar-3.3.0.tgz#12c0714668c55800f659e262d4962a97faf554a6"
+  integrity sha512-dGmKLDdT3Gdl7fBUe8XK+gAtGmzy5Fn0XkkWQuYxGIgWVPPse2CxFA5mtrlD0TOHaHjEUqkWNyP1XdHoJES/4A==
+  dependencies:
+    anymatch "~3.1.1"
+    braces "~3.0.2"
+    glob-parent "~5.1.0"
+    is-binary-path "~2.1.0"
+    is-glob "~4.0.1"
+    normalize-path "~3.0.0"
+    readdirp "~3.2.0"
+  optionalDependencies:
+    fsevents "~2.1.1"
+
 chokidar@^2.0.2:
   version "2.1.8"
   resolved "https://registry.yarnpkg.com/chokidar/-/chokidar-2.1.8.tgz#804b3a7b6a99358c3c5c61e71d8728f041cff917"
@@ -5188,6 +5213,11 @@ crypto-browserify@^3.11.0:
     randombytes "^2.0.0"
     randomfill "^1.0.3"
 
+css-selector-parser@^1.0.0:
+  version "1.3.0"
+  resolved "https://registry.yarnpkg.com/css-selector-parser/-/css-selector-parser-1.3.0.tgz#5f1ad43e2d8eefbfdc304fcd39a521664943e3eb"
+  integrity sha1-XxrUPi2O77/cME/NOaUhZklD4+s=
+
 csstype@^2.2.0, csstype@^2.5.7:
   version "2.6.9"
   resolved "https://registry.yarnpkg.com/csstype/-/csstype-2.6.9.tgz#05141d0cd557a56b8891394c1911c40c8a98d098"
@@ -6687,7 +6717,7 @@ fsevents@^1.2.7:
     bindings "^1.5.0"
     nan "^2.12.1"
 
-fsevents@~2.1.2:
+fsevents@~2.1.1, fsevents@~2.1.2:
   version "2.1.2"
   resolved "https://registry.yarnpkg.com/fsevents/-/fsevents-2.1.2.tgz#4c0a1fb34bc68e543b4b82a9ec392bfbda840805"
   integrity sha512-R4wDiBwZ0KzpgOWetKDug1FZcYhqYnUYKtfZYt4mD5SBz76q0KR4Q9o7GIPamsVPGmW3EYPPJ0dOOjvx32ldZA==
@@ -7259,6 +7289,11 @@ hast-util-from-parse5@^5.0.0:
     web-namespaces "^1.1.2"
     xtend "^4.0.1"
 
+hast-util-is-element@^1.0.0:
+  version "1.0.4"
+  resolved "https://registry.yarnpkg.com/hast-util-is-element/-/hast-util-is-element-1.0.4.tgz#059090a05cc02e275df1ad02caf8cb422fcd2e02"
+  integrity sha512-NFR6ljJRvDcyPP5SbV7MyPBgF47X3BsskLnmw1U34yL+X6YC0MoBx9EyMg8Jtx4FzGH95jw8+c1VPLHaRA0wDQ==
+
 hast-util-parse-selector@^2.0.0:
   version "2.2.3"
   resolved "https://registry.yarnpkg.com/hast-util-parse-selector/-/hast-util-parse-selector-2.2.3.tgz#57edd449103900c7f63fd9e6f694ffd7e4634719"
@@ -7278,6 +7313,29 @@ hast-util-raw@5.0.1:
     xtend "^4.0.1"
     zwitch "^1.0.0"
 
+hast-util-sanitize@^2.0.0:
+  version "2.0.2"
+  resolved "https://registry.yarnpkg.com/hast-util-sanitize/-/hast-util-sanitize-2.0.2.tgz#8a4299bccba6cc8836284466d446060d2ecb2f5c"
+  integrity sha512-ppfgtI6pVb0/dopboV/N2SZju/CKEJzLs6jm58NxoYU1c1ib+/sh14JV5bjLDOEYvyeb5hYIttFKanYm0rtnHQ==
+  dependencies:
+    xtend "^4.0.0"
+
+hast-util-to-html@^7.0.0:
+  version "7.1.0"
+  resolved "https://registry.yarnpkg.com/hast-util-to-html/-/hast-util-to-html-7.1.0.tgz#aa580e7b846438ee1e7af2bee6a650062eb0c3ec"
+  integrity sha512-RjvNL41bYnxTOA+s8W8mjhVxH1J0dXza9hlakVHbghFsfj3JO/lsq3DsR/Md2HbynS8y89/LA7k0lhtnYJ1Yzw==
+  dependencies:
+    ccount "^1.0.0"
+    comma-separated-tokens "^1.0.0"
+    hast-util-is-element "^1.0.0"
+    hast-util-whitespace "^1.0.0"
+    html-void-elements "^1.0.0"
+    property-information "^5.0.0"
+    space-separated-tokens "^1.0.0"
+    stringify-entities "^3.0.0"
+    unist-util-is "^4.0.0"
+    xtend "^4.0.0"
+
 hast-util-to-parse5@^5.0.0:
   version "5.1.1"
   resolved "https://registry.yarnpkg.com/hast-util-to-parse5/-/hast-util-to-parse5-5.1.1.tgz#cabf2dbe9ed988a5128fc708457b37cdf535a2e8"
@@ -7289,6 +7347,11 @@ hast-util-to-parse5@^5.0.0:
     xtend "^4.0.1"
     zwitch "^1.0.0"
 
+hast-util-whitespace@^1.0.0:
+  version "1.0.4"
+  resolved "https://registry.yarnpkg.com/hast-util-whitespace/-/hast-util-whitespace-1.0.4.tgz#e4fe77c4a9ae1cb2e6c25e02df0043d0164f6e41"
+  integrity sha512-I5GTdSfhYfAPNztx2xJRQpG8cuDSNt599/7YUn7Gx/WxNMsG+a835k97TDkFgk123cwjfwINaZknkKkphx/f2A==
+
 hastscript@^5.0.0:
   version "5.1.1"
   resolved "https://registry.yarnpkg.com/hastscript/-/hastscript-5.1.1.tgz#71726ee1e97220575d1f29a8e937387d99d48275"
@@ -7363,7 +7426,7 @@ html-tags@^3.1.0:
   resolved "https://registry.yarnpkg.com/html-tags/-/html-tags-3.1.0.tgz#7b5e6f7e665e9fb41f30007ed9e0d41e97fb2140"
   integrity sha512-1qYz89hW3lFDEazhjW0yVAV87lw8lVkrJocr72XmBkMKsoSVJCQx3W8BXsC7hO2qAt8BoVjYjtAcZ9perqGnNg==
 
-html-void-elements@^1.0.1:
+html-void-elements@^1.0.0, html-void-elements@^1.0.1:
   version "1.0.5"
   resolved "https://registry.yarnpkg.com/html-void-elements/-/html-void-elements-1.0.5.tgz#ce9159494e86d95e45795b166c2021c2cfca4483"
   integrity sha512-uE/TxKuyNIcx44cIWnjr/rfIATDH7ZaOMmstu0CwhFG1Dunhlp4OC6/NMbhiwoq5BpW0ubi303qnEk/PZj614w==
@@ -7824,7 +7887,7 @@ is-date-object@^1.0.1:
   resolved "https://registry.yarnpkg.com/is-date-object/-/is-date-object-1.0.2.tgz#bda736f2cd8fd06d32844e7743bfa7494c3bfd7e"
   integrity sha512-USlDT524woQ08aoZFzh3/Z6ch9Y/EWXEHQ/AaRN0SkKq4t2Jw2R2339tSXmwuVoY7LLlBCbOIlx2myP/L5zk0g==
 
-is-decimal@^1.0.0:
+is-decimal@^1.0.0, is-decimal@^1.0.2:
   version "1.0.4"
   resolved "https://registry.yarnpkg.com/is-decimal/-/is-decimal-1.0.4.tgz#65a3a5958a1c5b63a706e1b333d7cd9f630d3fa5"
   integrity sha512-RGdriMmQQvZ2aqaQq3awNA6dCGtKpiDFcOzrTWrDAT2MiWrKQVPmxLGHl7Y2nNu6led0kEyoX0enY0qXYsv9zw==
@@ -9099,6 +9162,13 @@ log-symbols@2.2.0, log-symbols@^2.1.0, log-symbols@^2.2.0:
   dependencies:
     chalk "^2.0.1"
 
+log-symbols@3.0.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/log-symbols/-/log-symbols-3.0.0.tgz#f3a08516a5dea893336a7dee14d18a1cfdab77c4"
+  integrity sha512-dSkNGuI7iG3mfvDzUuYZyvk5dD9ocYCYzNU6CYDE6+Xqd+gwme6Z00NS3dUh8mq/73HaEtT7m6W+yUPtU6BZnQ==
+  dependencies:
+    chalk "^2.4.2"
+
 log-symbols@^1.0.0, log-symbols@^1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/log-symbols/-/log-symbols-1.0.2.tgz#376ff7b58ea3086a0f09facc74617eca501e1a18"
@@ -9375,6 +9445,13 @@ mdast-util-definitions@^1.2.0, mdast-util-definitions@^1.2.3:
   dependencies:
     unist-util-visit "^1.0.0"
 
+mdast-util-definitions@^2.0.0:
+  version "2.0.1"
+  resolved "https://registry.yarnpkg.com/mdast-util-definitions/-/mdast-util-definitions-2.0.1.tgz#2c931d8665a96670639f17f98e32c3afcfee25f3"
+  integrity sha512-Co+DQ6oZlUzvUR7JCpP249PcexxygiaKk9axJh+eRzHDZJk2julbIdKB4PXHVxdBuLzvJ1Izb+YDpj2deGMOuA==
+  dependencies:
+    unist-util-visit "^2.0.0"
+
 mdast-util-to-hast@7.0.0:
   version "7.0.0"
   resolved "https://registry.yarnpkg.com/mdast-util-to-hast/-/mdast-util-to-hast-7.0.0.tgz#589b562ce1ae0a7849e6c38536a9e7bc4f415e54"
@@ -9390,12 +9467,27 @@ mdast-util-to-hast@7.0.0:
     unist-util-position "^3.0.0"
     unist-util-visit "^2.0.0"
 
+mdast-util-to-hast@^8.0.0:
+  version "8.2.0"
+  resolved "https://registry.yarnpkg.com/mdast-util-to-hast/-/mdast-util-to-hast-8.2.0.tgz#adf9f824defcd382e53dd7bace4282a45602ac67"
+  integrity sha512-WjH/KXtqU66XyTJQ7tg7sjvTw1OQcVV0hKdFh3BgHPwZ96fSBCQ/NitEHsN70Mmnggt+5eUUC7pCnK+2qGQnCA==
+  dependencies:
+    collapse-white-space "^1.0.0"
+    detab "^2.0.0"
+    mdast-util-definitions "^2.0.0"
+    mdurl "^1.0.0"
+    trim-lines "^1.0.0"
+    unist-builder "^2.0.0"
+    unist-util-generated "^1.0.0"
+    unist-util-position "^3.0.0"
+    unist-util-visit "^2.0.0"
+
 mdast-util-to-string@^1.0.0:
   version "1.0.8"
   resolved "https://registry.yarnpkg.com/mdast-util-to-string/-/mdast-util-to-string-1.0.8.tgz#a414cee45ad4bef93a60f32f48266d43e263d88f"
   integrity sha512-GBracya0dOzckEEizUBzfrkWRLCHMsppuU97LPUriY9kWnYyGFWTx4VDW+sUcj2LneBz/Tp1aYp3aUCibzjtWg==
 
-mdurl@^1.0.1:
+mdurl@^1.0.0, mdurl@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/mdurl/-/mdurl-1.0.1.tgz#fe85b2ec75a59037f2adfec100fd6c601761152e"
   integrity sha1-/oWy7HWlkDfyrf7BAP1sYBdhFS4=
@@ -9614,6 +9706,11 @@ minimist@1.2.0, minimist@^1.1.1, minimist@^1.1.3, minimist@^1.2.0:
   resolved "https://registry.yarnpkg.com/minimist/-/minimist-1.2.0.tgz#a35008b20f41383eec1fb914f4cd5df79a264284"
   integrity sha1-o1AIsg9BOD7sH7kU9M1d95omQoQ=
 
+minimist@^1.2.5:
+  version "1.2.5"
+  resolved "https://registry.yarnpkg.com/minimist/-/minimist-1.2.5.tgz#67d66014b66a6a8aaa0c083c5fd58df4e4e97602"
+  integrity sha512-FM9nNUYrRBAELZQT3xeZQ7fmMOBg6nWNmJKTcgsJeaLstP/UODVpGsr5OhXhhXg6f+qtJ8uiZ+PUxkDWcgIXLw==
+
 minimist@~0.0.1:
   version "0.0.10"
   resolved "https://registry.yarnpkg.com/minimist/-/minimist-0.0.10.tgz#de3f98543dbf96082be48ad1a0c7cda836301dcf"
@@ -9677,6 +9774,13 @@ mkdirp@0.5.1, mkdirp@^0.5.0, mkdirp@^0.5.1, mkdirp@~0.5.1:
   dependencies:
     minimist "0.0.8"
 
+mkdirp@0.5.3:
+  version "0.5.3"
+  resolved "https://registry.yarnpkg.com/mkdirp/-/mkdirp-0.5.3.tgz#5a514b7179259287952881e94410ec5465659f8c"
+  integrity sha512-P+2gwrFqx8lhew375MQHHeTlY8AuOJSrGf0R5ddkEndUkmwpgUob/vQuBD1V22/Cw1/lJr4x+EjllSezBThzBg==
+  dependencies:
+    minimist "^1.2.5"
+
 mocha@^6.2.2:
   version "6.2.2"
   resolved "https://registry.yarnpkg.com/mocha/-/mocha-6.2.2.tgz#5d8987e28940caf8957a7d7664b910dc5b2fea20"
@@ -9706,6 +9810,36 @@ mocha@^6.2.2:
     yargs-parser "13.1.1"
     yargs-unparser "1.6.0"
 
+mocha@^7.1.1:
+  version "7.1.1"
+  resolved "https://registry.yarnpkg.com/mocha/-/mocha-7.1.1.tgz#89fbb30d09429845b1bb893a830bf5771049a441"
+  integrity sha512-3qQsu3ijNS3GkWcccT5Zw0hf/rWvu1fTN9sPvEd81hlwsr30GX2GcDSSoBxo24IR8FelmrAydGC6/1J5QQP4WA==
+  dependencies:
+    ansi-colors "3.2.3"
+    browser-stdout "1.3.1"
+    chokidar "3.3.0"
+    debug "3.2.6"
+    diff "3.5.0"
+    escape-string-regexp "1.0.5"
+    find-up "3.0.0"
+    glob "7.1.3"
+    growl "1.10.5"
+    he "1.2.0"
+    js-yaml "3.13.1"
+    log-symbols "3.0.0"
+    minimatch "3.0.4"
+    mkdirp "0.5.3"
+    ms "2.1.1"
+    node-environment-flags "1.0.6"
+    object.assign "4.1.0"
+    strip-json-comments "2.0.1"
+    supports-color "6.0.0"
+    which "1.3.1"
+    wide-align "1.1.3"
+    yargs "13.3.2"
+    yargs-parser "13.1.2"
+    yargs-unparser "1.6.0"
+
 modify-values@^1.0.0:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/modify-values/-/modify-values-1.0.1.tgz#b3939fa605546474e3e3e3c63d64bd43b4ee6022"
@@ -9864,6 +9998,14 @@ node-environment-flags@1.0.5:
     object.getownpropertydescriptors "^2.0.3"
     semver "^5.7.0"
 
+node-environment-flags@1.0.6:
+  version "1.0.6"
+  resolved "https://registry.yarnpkg.com/node-environment-flags/-/node-environment-flags-1.0.6.tgz#a30ac13621f6f7d674260a54dede048c3982c088"
+  integrity sha512-5Evy2epuL+6TM0lCQGpFIj6KwiEsGh1SrHUhTbNX+sLbBtjidPZFAnVK9y5yU1+h//RitLbRHTIMyxQPtxMdHw==
+  dependencies:
+    object.getownpropertydescriptors "^2.0.3"
+    semver "^5.7.0"
+
 node-fetch-npm@^2.0.2:
   version "2.0.2"
   resolved "https://registry.yarnpkg.com/node-fetch-npm/-/node-fetch-npm-2.0.2.tgz#7258c9046182dca345b4208eda918daf33697ff7"
@@ -9989,6 +10131,11 @@ normalize-url@^3.3.0:
   resolved "https://registry.yarnpkg.com/normalize-url/-/normalize-url-3.3.0.tgz#b2e1c4dc4f7c6d57743df733a4f5978d18650559"
   integrity sha512-U+JJi7duF1o+u2pynbp2zXDW2/PADgC30f0GsHZtRh+HOcXHnw137TrNlyxxRvWW5fjKd3bcLHPxofWuCjaeZg==
 
+not@^0.1.0:
+  version "0.1.0"
+  resolved "https://registry.yarnpkg.com/not/-/not-0.1.0.tgz#c9691c1746c55dcfbe54cbd8bd4ff041bc2b519d"
+  integrity sha1-yWkcF0bFXc++VMvYvU/wQbwrUZ0=
+
 now-and-later@^2.0.0:
   version "2.0.1"
   resolved "https://registry.yarnpkg.com/now-and-later/-/now-and-later-2.0.1.tgz#8e579c8685764a7cc02cb680380e94f43ccb1f7c"
@@ -10098,6 +10245,13 @@ npmlog@^4.0.1, npmlog@^4.1.2:
     gauge "~2.7.3"
     set-blocking "~2.0.0"
 
+nth-check@^1.0.0:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/nth-check/-/nth-check-1.0.2.tgz#b2bd295c37e3dd58a3bf0700376663ba4d9cf05c"
+  integrity sha512-WeBOdju8SnzPN5vTUJYxYUxLeXpCaVP5i5e0LF8fg7WORF2Wd7wFX/pk0tYZk7s8T+J7VLy0Da6J1+wCT0AtHg==
+  dependencies:
+    boolbase "~1.0.0"
+
 number-is-nan@^1.0.0:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/number-is-nan/-/number-is-nan-1.0.1.tgz#097b602b53422a522c1afb8790318336941a011d"
@@ -10457,6 +10611,18 @@ parse-entities@^1.0.2, parse-entities@^1.1.0, parse-entities@^1.1.2:
     is-decimal "^1.0.0"
     is-hexadecimal "^1.0.0"
 
+parse-entities@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/parse-entities/-/parse-entities-2.0.0.tgz#53c6eb5b9314a1f4ec99fa0fdf7ce01ecda0cbe8"
+  integrity sha512-kkywGpCcRYhqQIchaWqZ875wzpS/bMKhz5HnN3p7wveJTkTtyAB/AlnS0f8DFSqYW1T82t6yEAkEcB+A1I3MbQ==
+  dependencies:
+    character-entities "^1.0.0"
+    character-entities-legacy "^1.0.0"
+    character-reference-invalid "^1.0.0"
+    is-alphanumerical "^1.0.0"
+    is-decimal "^1.0.0"
+    is-hexadecimal "^1.0.0"
+
 parse-github-repo-url@^1.3.0:
   version "1.4.1"
   resolved "https://registry.yarnpkg.com/parse-github-repo-url/-/parse-github-repo-url-1.4.1.tgz#9e7d8bb252a6cb6ba42595060b7bf6df3dbc1f50"
@@ -11486,6 +11652,13 @@ readdirp@^2.2.1:
     micromatch "^3.1.10"
     readable-stream "^2.0.2"
 
+readdirp@~3.2.0:
+  version "3.2.0"
+  resolved "https://registry.yarnpkg.com/readdirp/-/readdirp-3.2.0.tgz#c30c33352b12c96dfb4b895421a49fd5a9593839"
+  integrity sha512-crk4Qu3pmXwgxdSgGhgA/eXiJAPQiX4GMOZZMXnqKxHX7TaoL+3gQVo/WeuAiogr07DpnfjIMpXXa+PAIvwPGQ==
+  dependencies:
+    picomatch "^2.0.4"
+
 readdirp@~3.3.0:
   version "3.3.0"
   resolved "https://registry.yarnpkg.com/readdirp/-/readdirp-3.3.0.tgz#984458d13a1e42e2e9f5841b129e162f369aff17"
@@ -11657,6 +11830,16 @@ remark-external-links@^5.0.0:
     space-separated-tokens "^1.1.2"
     unist-util-visit "^1.4.0"
 
+remark-html@^11.0.1:
+  version "11.0.1"
+  resolved "https://registry.yarnpkg.com/remark-html/-/remark-html-11.0.1.tgz#fe12671be9dd67e75dd90dfb4d78c9d42f2e11ec"
+  integrity sha512-bz7tSu9kDbaRNaiqQWrgXITkqJsZXoc2fjau+ms7WA4vflDoB+xMdY0QfNhUpGgmAv4SdDD1m+3BxWRHLizmiQ==
+  dependencies:
+    hast-util-sanitize "^2.0.0"
+    hast-util-to-html "^7.0.0"
+    mdast-util-to-hast "^8.0.0"
+    xtend "^4.0.1"
+
 remark-mdx@^1.5.7:
   version "1.5.7"
   resolved "https://registry.yarnpkg.com/remark-mdx/-/remark-mdx-1.5.7.tgz#bdeb83e7e625a8e1e446c233c6cb30dd5f0cfd98"
@@ -11713,6 +11896,28 @@ remark-parse@^4.0.0:
     vfile-location "^2.0.0"
     xtend "^4.0.1"
 
+remark-parse@^8.0.0:
+  version "8.0.0"
+  resolved "https://registry.yarnpkg.com/remark-parse/-/remark-parse-8.0.0.tgz#0aaae4b49e607ee7e972a6cf688026f46bbf6d1a"
+  integrity sha512-Ck14G1Ns/GEPXhSw6m1Uv28kMtVk63e59NyL+QlhBBwBdIUXROM6MPfBehPhW6TW2d73batMdZsKwuxl5i3tEA==
+  dependencies:
+    ccount "^1.0.0"
+    collapse-white-space "^1.0.2"
+    is-alphabetical "^1.0.0"
+    is-decimal "^1.0.0"
+    is-whitespace-character "^1.0.0"
+    is-word-character "^1.0.0"
+    markdown-escapes "^1.0.0"
+    parse-entities "^2.0.0"
+    repeat-string "^1.5.4"
+    state-toggle "^1.0.0"
+    trim "0.0.1"
+    trim-trailing-lines "^1.0.0"
+    unherit "^1.0.4"
+    unist-util-remove-position "^2.0.0"
+    vfile-location "^3.0.0"
+    xtend "^4.0.1"
+
 remark-slug@^5.1.2:
   version "5.1.2"
   resolved "https://registry.yarnpkg.com/remark-slug/-/remark-slug-5.1.2.tgz#715ecdef8df1226786204b1887d31ab16aa24609"
@@ -12722,6 +12927,17 @@ string_decoder@~1.1.1:
   dependencies:
     safe-buffer "~5.1.0"
 
+stringify-entities@^3.0.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/stringify-entities/-/stringify-entities-3.0.0.tgz#455abe501f8b7859ba5726a25a8872333c65b0a7"
+  integrity sha512-h7NJJIssprqlyjHT2eQt2W1F+MCcNmwPGlKb0bWEdET/3N44QN3QbUF/ueKCgAssyKRZ3Br9rQ7FcXjHr0qLHw==
+  dependencies:
+    character-entities-html4 "^1.0.0"
+    character-entities-legacy "^1.0.0"
+    is-alphanumerical "^1.0.0"
+    is-decimal "^1.0.2"
+    is-hexadecimal "^1.0.0"
+
 stringify-object@^3.2.2, stringify-object@^3.3.0:
   version "3.3.0"
   resolved "https://registry.yarnpkg.com/stringify-object/-/stringify-object-3.3.0.tgz#703065aefca19300d3ce88af4f5b3956d7556629"
@@ -13441,6 +13657,18 @@ unified@^6.1.5:
     vfile "^2.0.0"
     x-is-string "^0.1.0"
 
+unified@^9.0.0:
+  version "9.0.0"
+  resolved "https://registry.yarnpkg.com/unified/-/unified-9.0.0.tgz#12b099f97ee8b36792dbad13d278ee2f696eed1d"
+  integrity sha512-ssFo33gljU3PdlWLjNp15Inqb77d6JnJSfyplGJPT/a+fNRNyCBeveBAYJdO5khKdF6WVHa/yYCC7Xl6BDwZUQ==
+  dependencies:
+    bail "^1.0.0"
+    extend "^3.0.0"
+    is-buffer "^2.0.0"
+    is-plain-obj "^2.0.0"
+    trough "^1.0.0"
+    vfile "^4.0.0"
+
 union-value@^1.0.0:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/union-value/-/union-value-1.0.1.tgz#0b6fe7b835aecda61c6ea4d4f02c14221e109847"
@@ -13488,7 +13716,7 @@ unist-util-is@^3.0.0:
   resolved "https://registry.yarnpkg.com/unist-util-is/-/unist-util-is-3.0.0.tgz#d9e84381c2468e82629e4a5be9d7d05a2dd324cd"
   integrity sha512-sVZZX3+kspVNmLWBPAB6r+7D9ZgAFPNWm66f7YNb420RlQSbn+n8rG8dGZSkrER7ZIXGQYNm5pqC3v3HopH24A==
 
-unist-util-is@^4.0.0:
+unist-util-is@^4.0.0, unist-util-is@^4.0.2:
   version "4.0.2"
   resolved "https://registry.yarnpkg.com/unist-util-is/-/unist-util-is-4.0.2.tgz#c7d1341188aa9ce5b3cff538958de9895f14a5de"
   integrity sha512-Ofx8uf6haexJwI1gxWMGg6I/dLnF2yE+KibhD3/diOqY2TinLcqHXCV6OI5gFVn3xQqDH+u0M625pfKwIwgBKQ==
@@ -13505,6 +13733,13 @@ unist-util-remove-position@^1.0.0:
   dependencies:
     unist-util-visit "^1.1.0"
 
+unist-util-remove-position@^2.0.0:
+  version "2.0.1"
+  resolved "https://registry.yarnpkg.com/unist-util-remove-position/-/unist-util-remove-position-2.0.1.tgz#5d19ca79fdba712301999b2b73553ca8f3b352cc"
+  integrity sha512-fDZsLYIe2uT+oGFnuZmy73K6ZxOPG/Qcm+w7jbEjaFcJgbQ6cqjs/eSPzXhsmGpAsWPkqZM9pYjww5QTn3LHMA==
+  dependencies:
+    unist-util-visit "^2.0.0"
+
 unist-util-remove@^1.0.0:
   version "1.0.3"
   resolved "https://registry.yarnpkg.com/unist-util-remove/-/unist-util-remove-1.0.3.tgz#58ec193dfa84b52d5a055ffbc58e5444eb8031a3"
@@ -13512,6 +13747,17 @@ unist-util-remove@^1.0.0:
   dependencies:
     unist-util-is "^3.0.0"
 
+unist-util-select@^3.0.1:
+  version "3.0.1"
+  resolved "https://registry.yarnpkg.com/unist-util-select/-/unist-util-select-3.0.1.tgz#787fc452db9ba77f0ade0e7dc53c3d9d4acc79c7"
+  integrity sha512-VQpTuqZVJlRbosQdnLdTPIIqwZeU70YZ5aMBOqtFNGeeCdYn6ORZt/9RiaVlbl06ocuf58SVMoFa7a13CSGPMA==
+  dependencies:
+    css-selector-parser "^1.0.0"
+    not "^0.1.0"
+    nth-check "^1.0.0"
+    unist-util-is "^4.0.0"
+    zwitch "^1.0.0"
+
 unist-util-stringify-position@^1.0.0, unist-util-stringify-position@^1.1.1:
   version "1.1.2"
   resolved "https://registry.yarnpkg.com/unist-util-stringify-position/-/unist-util-stringify-position-1.1.2.tgz#3f37fcf351279dcbca7480ab5889bb8a832ee1c6"
@@ -13539,7 +13785,7 @@ unist-util-visit-parents@^3.0.0:
     "@types/unist" "^2.0.0"
     unist-util-is "^4.0.0"
 
-unist-util-visit@2.0.2, unist-util-visit@^2.0.0:
+unist-util-visit@2.0.2, unist-util-visit@^2.0.0, unist-util-visit@^2.0.2:
   version "2.0.2"
   resolved "https://registry.yarnpkg.com/unist-util-visit/-/unist-util-visit-2.0.2.tgz#3843782a517de3d2357b4c193b24af2d9366afb7"
   integrity sha512-HoHNhGnKj6y+Sq+7ASo2zpVdfdRifhTgX2KTU3B/sO/TTlZchp7E3S4vjRzDJ7L60KmrCPsQkVK3lEF3cz36XQ==
@@ -13752,6 +13998,11 @@ vfile-location@^2.0.0:
   resolved "https://registry.yarnpkg.com/vfile-location/-/vfile-location-2.0.6.tgz#8a274f39411b8719ea5728802e10d9e0dff1519e"
   integrity sha512-sSFdyCP3G6Ka0CEmN83A2YCMKIieHx0EDaj5IDP4g1pa5ZJ4FJDvpO0WODLxo4LUX4oe52gmSCK7Jw4SBghqxA==
 
+vfile-location@^3.0.0:
+  version "3.0.1"
+  resolved "https://registry.yarnpkg.com/vfile-location/-/vfile-location-3.0.1.tgz#d78677c3546de0f7cd977544c367266764d31bb3"
+  integrity sha512-yYBO06eeN/Ki6Kh1QAkgzYpWT1d3Qln+ZCtSbJqFExPl1S3y2qqotJQXoh6qEvl/jDlgpUJolBn3PItVnnZRqQ==
+
 vfile-message@^1.0.0:
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/vfile-message/-/vfile-message-1.1.1.tgz#5833ae078a1dfa2d96e9647886cd32993ab313e1"
@@ -14337,6 +14588,14 @@ yargs-parser@13.1.1, yargs-parser@^13.1.1:
     camelcase "^5.0.0"
     decamelize "^1.2.0"
 
+yargs-parser@13.1.2, yargs-parser@^13.1.2:
+  version "13.1.2"
+  resolved "https://registry.yarnpkg.com/yargs-parser/-/yargs-parser-13.1.2.tgz#130f09702ebaeef2650d54ce6e3e5706f7a4fb38"
+  integrity sha512-3lbsNRf/j+A4QuSZfDRA7HRSfWrzO0YjqTJd5kjAq37Zep1CEgaYmrH9Q3GwPiB9cHyd1Y1UwggGhJGoxipbzg==
+  dependencies:
+    camelcase "^5.0.0"
+    decamelize "^1.2.0"
+
 yargs-parser@^10.0.0:
   version "10.1.0"
   resolved "https://registry.yarnpkg.com/yargs-parser/-/yargs-parser-10.1.0.tgz#7202265b89f7e9e9f2e5765e0fe735a905edbaa8"
@@ -14385,6 +14644,22 @@ yargs@13.3.0, yargs@^13.3.0:
     y18n "^4.0.0"
     yargs-parser "^13.1.1"
 
+yargs@13.3.2:
+  version "13.3.2"
+  resolved "https://registry.yarnpkg.com/yargs/-/yargs-13.3.2.tgz#ad7ffefec1aa59565ac915f82dccb38a9c31a2dd"
+  integrity sha512-AX3Zw5iPruN5ie6xGRIDgqkT+ZhnRlZMLMHAs8tg7nRruy2Nb+i5o9bwghAogtM08q1dpr2LVoS8KSTMYpWXUw==
+  dependencies:
+    cliui "^5.0.0"
+    find-up "^3.0.0"
+    get-caller-file "^2.0.1"
+    require-directory "^2.1.1"
+    require-main-filename "^2.0.0"
+    set-blocking "^2.0.0"
+    string-width "^3.0.0"
+    which-module "^2.0.0"
+    y18n "^4.0.0"
+    yargs-parser "^13.1.2"
+
 yargs@^12.0.2:
   version "12.0.5"
   resolved "https://registry.yarnpkg.com/yargs/-/yargs-12.0.5.tgz#05f5997b609647b64f66b81e3b4b10a368e7ad13"