feat: add GitHub button to homepage (#106)

### Description
<!-- Please add PR description (don't leave blank) - example: This PR
[adds/removes/fixes/replaces] the [feature/bug/etc] -->

This Pull Request adds the GitHub button to the homepage of the web app
with a link back to the project repo and a display of project stars
count

### Screenshots/Screencasts
<!-- Please provide screenshots or video recording that demos your
changes (especially if it's a visual change) -->


![image](https://github.com/user-attachments/assets/16b6fafc-9aff-4ffa-93e3-4923709eff13)

src/pages/index.astro

@@ -10,8 +10,12 @@ const dictionary = await getCollection("dictionary");
 <BaseLayout 
 	pageTitle="Jargons.dev"
 	subtitle="Simplified Meaning & Definition to Technical Terms"
+	class:list="min-h-screen flex flex-col"
 >
-	<main class="flex flex-col max-w-screen-lg p-5 justify-center mx-auto min-h-screen">
+	<nav class="@container flex items-center justify-end px-5 md:px-6 py-4">
+		<iframe src="https://ghbtns.com/github-btn.html?user=jargonsdev&repo=jargons.dev&type=watch&count=true&size=large" frameborder="0" scrolling="0" width="120" height="30" title="GitHub"></iframe>
+	</nav>
+	<main class="w-full flex flex-col grow max-w-screen-lg p-5 justify-center mx-auto">
 		<!-- Title -->
 		<div class="mb-4 md:mb-6">
 			<h1 class="relative text-5xl md:text-7xl lg:text-8xl font-black w-fit">