Create getSortedPosts util function

src/utils/getSortedPosts.ts

@@ -0,0 +1,20 @@
+import type { MarkdownInstance } from "astro";
+
+interface Frontmatter {
+  title: string;
+  description: string;
+  author: string;
+  datetime: string;
+  slug: string;
+  featured: boolean;
+  tags: string[];
+}
+
+const getSortedPosts = (posts: MarkdownInstance<Frontmatter>[]) =>
+  posts.sort(
+    (a, b) =>
+      Math.floor(new Date(b.frontmatter.datetime).getTime() / 1000) -
+      Math.floor(new Date(a.frontmatter.datetime).getTime() / 1000)
+  );
+
+export default getSortedPosts;