chore: wrote a blogpost on @lion/ui (#1946)

* chore: wrote a blogpost on @lion/ui

* Update docs/blog/introducing-lion-ui.md

Co-authored-by: Thijs Louisse <thijs.louisse@ing.com>

* Update docs/blog/introducing-lion-ui.md

Co-authored-by: gerjanvangeest <gerjanvangeest@users.noreply.github.com>

* Update introducing-lion-ui.md

Removed placeholder cover image

---------

Co-authored-by: Thijs Louisse <thijs.louisse@ing.com>
Co-authored-by: gerjanvangeest <gerjanvangeest@users.noreply.github.com>

docs/blog/introducing-lion-ui.md

@@ -0,0 +1,55 @@
+---
+title: Introducing Lion UI
+published: false
+description: Lion introduces the new package @lion/ui which is a collection of all lion UI components.
+date: 2023-03-20
+tags: [javascript]
+---
+
+### A new package
+
+Lion introduces a new package `@lion/ui` which is a collection of UI components that can be used in your application.
+It contains all the components/systems that used to be distributed via separate @lion/\* packages.
+This brings back around 40 packages to just 1.
+
+### Better dependency management
+
+Since `@lion/ui` is now a single package, the dependencies of the individual components are now managed in a single
+`package.json` file. This results in a single folder of dependencies for all components instead of a folder
+for each component separately.
+
+This means you will now have less dependencies that are easier to manage.
+
+### New entrypoints
+
+All components are now imported from @lion/ui instead of @lion/\* packages and therefore this is a breaking change.
+Where before you would import from `@lion/<package>`, you will now import from `@lion/ui/<package>.js`.
+
+For example:
+
+```diff
+- import { LionAccordion } from '@lion/accordion';
++ import { LionAccordion } from '@lion/ui/accordion.js';
+```
+
+Element registrations have changed as well. For example:
+
+```diff
+- import '@lion/accordion/define';
++ import '@lion/ui/define/lion-accordion.js';
+```
+
+All available entrypoints for the packages in Lion can now easily be found in the `/packages/ui/exports` folder which
+makes the public API much more clear. This is now possible because Node.js supports the `exports` field in `package.json`
+where these entrypoints are defined.
+
+For example, `@lion/ui/accordion.js` maps to `/packages/exports/accordion.js` and `@lion/ui/define/lion-accordion.js`
+maps to `/packages/exports/define/lion-accordion.js`.
+
+Support for this `exports` field was added to TypeScript 4.7 so for that reason, `@lion/ui` only supports TypeScript
+4.7+ with `"moduleResolution": "Node16"` or `"moduleResolution": "NodeNext"`.
+
+### A new changelog
+
+`@lion/ui` has [a new single CHANGELOG.md]( https://github.com/ing-bank/lion/blob/master/packages/ui/CHANGELOG.md) in `/packages/ui` for the whole package. The older individual changelogs can be
+found in the `/packages/ui/_legacy-changelogs` folder.