feat: sample interactive element on landing page

src/components/hello-world.js

@@ -7,7 +7,7 @@ class HelloWorld extends WebComponent {
     let count = 0;
     this.onclick = () => {
       console.log("Clicked!");
-      this.setAttribute("name", `I was clicked ${++count} times!`);
+      this.setAttribute("name", `Clicked ${++count}x`);
     };
     this.setAttribute("title", "Click me please");
   }

src/pages/index.html

@@ -8,6 +8,10 @@
         <strong>McFly</strong> is a full-stack no-framework framework that
         assists developers in leveraging the web platform.
       </p>
+      <p>
+        Here's a sample interactive custom element:
+        <hello-world name="McFly"></hello-world>
+      </p>
       <p>
         Start at the very basic of writing HTML files and enhance with standard
         web technologies or go advanced as you like, at your own pace.