feat: add header component and update blog layout

- Introduced a new Header component for site navigation.
- Integrated Header into BaseLayout for consistent site structure.
- Updated blog post layout to include the post title in a dedicated section.
- Minor update to README for license clarity.

src/pages/blog/[...slug].astro

@@ -32,11 +32,13 @@ const formattedDate = dayjs(post.data.pubDate.toString()).format("MMMM DD, YYYY"
 
 <Layout description={post.data.description} title={post.data.title}>
 	<article>
+		<section>
+			<h1>{post.data.title}</h1>
+		</section>
+
 		<section>
 			<p>
 				<small>
-					<a href="/">&lt; Home</a>
-					<span>&nbsp;•&nbsp;</span>
 					Posted
 					<time datetime={post.data.pubDate.toISOString()}>{formattedDate}</time>
 					by&nbsp;{post.data.author}
@@ -46,10 +48,6 @@ const formattedDate = dayjs(post.data.pubDate.toString()).format("MMMM DD, YYYY"
 			</p>
 		</section>
 
-		<section>
-			<h1>{post.data.title}</h1>
-		</section>
-
 		<section>
 			<Content />
 		</section>