chore: update blog routing and header link

- Removed the redirects for the blog route in the configuration.
- Updated the blog link in the Header component to include a trailing slash.
- Added a new index page for the blog to display all posts.

src/components/Header.astro

@@ -18,5 +18,5 @@
 
 <header>
 	<a href="/">Home</a>
-	<a href="/blog">Blog</a>
+	<a href="/blog/">Blog</a>
 </header>

src/pages/blog/index.astro

@@ -0,0 +1,17 @@
+---
+import { getCollection } from "astro:content";
+import Layout from "../../layouts/BaseLayout.astro";
+import PostSummary from "../../components/PostSummary.astro";
+
+const posts = await getCollection("blog", ({ data }) => {
+	return data.draft !== true;
+});
+
+posts.sort((a, b) => b.data.pubDate.getTime() - a.data.pubDate.getTime());
+---
+
+<Layout>
+	<section style={{ "margin-top": "3rem" }}>
+		{posts.map((post) => <PostSummary post={post} />)}
+	</section>
+</Layout>