feat(templates): use vanilla by default

templates/basic/src/pages/index.html

@@ -25,7 +25,7 @@
     <main>
       <h2>Welcome to {{ project.name }}</h2>
       <p>
-        Here's a vanilla custom element: <my-hello-world />
+        Here's a vanilla custom element: <vanilla-hello-world />
       </p>
       <code-block language="js">
 class HelloWorld extends HTMLElement {