refactor: enhance PostElement structure and update blog schema

- Wrapped the post link in an <article> tag for improved semantic structure.
- Updated blogSchema to include posts for better structured data representation.
- Adjusted the blog index to utilize the new posts parameter for enhanced SEO.

src/utils/schemas/blogSchema.ts

@@ -1,13 +1,24 @@
-import type { WithContext, Blog } from "schema-dts";
+import type { WithContext, CollectionPage } from "schema-dts";
+import type { CollectionEntry } from "astro:content";
 
 export type BlogSchemaParams = {
 	readonly siteUrl: string;
 	readonly title: string;
+	readonly posts: CollectionEntry<"blog">[];
 };
 
-export default ({ siteUrl, title }: BlogSchemaParams): WithContext<Blog> => ({
+export default ({ siteUrl, title, posts }: BlogSchemaParams): WithContext<CollectionPage> => ({
 	"@context": "https://schema.org",
-	"@type": "Blog",
+	"@type": "CollectionPage",
 	"url": new URL("/blog/", siteUrl).toString(),
 	"name": title,
+	"mainEntity": {
+		"@type": "ItemList",
+		"itemListElement": posts.map((post, index) => ({
+			"@type": "ListItem",
+			"position": index + 1,
+			"url": new URL(`/blog/${post.slug}`, siteUrl).toString(),
+			"name": post.data.title,
+		})),
+	},
 });