feat(blog): enhance blog functionality and SEO

- Added a new '/blog' route to middleware for improved navigation.
- Updated sitemap to dynamically include blog posts and series URLs.
- Enhanced blog page metadata with Open Graph and Twitter card information.
- Implemented structured data for blog posts and series to improve SEO.
- Removed outdated blog post "Week 1: De Kickoff" from content.
- Introduced optional OG image field in blog frontmatter for better sharing visuals.

app/sitemap.ts

@@ -7,6 +7,7 @@
 
 import type { MetadataRoute } from 'next'
 import { getAllReleases } from '@/lib/mdx/documentatie'
+import { getAllPosts, getAllSeries } from '@/lib/mdx/blog'
 
 export default async function sitemap(): Promise<MetadataRoute.Sitemap> {
   const baseUrl = process.env.NEXT_PUBLIC_APP_URL || 'https://aispeedrun.vercel.app'
@@ -27,6 +28,29 @@ export default async function sitemap(): Promise<MetadataRoute.Sitemap> {
     }
   })
 
+  // Fetch all blog posts dynamically
+  const posts = await getAllPosts()
+  const postUrls: MetadataRoute.Sitemap = posts.map((post) => {
+    const postDate = new Date(post.frontmatter.date)
+    const isValidDate = !isNaN(postDate.getTime())
+
+    return {
+      url: `${baseUrl}/blog/serie/${post.seriesId}/${post.slug}`,
+      lastModified: isValidDate ? postDate : currentDate,
+      changeFrequency: 'monthly',
+      priority: 0.7,
+    }
+  })
+
+  // Fetch all blog series
+  const series = await getAllSeries()
+  const seriesUrls: MetadataRoute.Sitemap = series.map((serie) => ({
+    url: `${baseUrl}/blog/serie/${serie.id}`,
+    lastModified: currentDate,
+    changeFrequency: 'weekly',
+    priority: 0.8,
+  }))
+
   return [
     {
       url: baseUrl,
@@ -34,12 +58,20 @@ export default async function sitemap(): Promise<MetadataRoute.Sitemap> {
       changeFrequency: 'weekly',
       priority: 1.0,
     },
+    {
+      url: `${baseUrl}/blog`,
+      lastModified: currentDate,
+      changeFrequency: 'weekly',
+      priority: 0.9,
+    },
     {
       url: `${baseUrl}/documentatie`,
       lastModified: currentDate,
       changeFrequency: 'weekly',
       priority: 0.9,
     },
+    ...seriesUrls,
+    ...postUrls,
     ...releaseUrls,
     {
       url: `${baseUrl}/contact`,