add template + document framework in root README

template/README.md: stripped to a one-liner bootstrap command.
README.md: full project docs (structure, add page, add component, build.sh).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Signed-off-by: GnomeZworc <nicolas.boufidjeline@g3e.fr>

template/sources/pages/home/home.js

@@ -0,0 +1,14 @@
+class HomePage extends HTMLElement {
+  connectedCallback() {
+    this.innerHTML = `
+      <div class="home">
+        <h2>Bienvenue</h2>
+        <p>Modifiez cette page dans <code>sources/pages/home/</code>.</p>
+      </div>
+    `
+  }
+}
+
+customElements.define('home-page', HomePage)
+
+export function init(_main) {}