feat: enhance blog and SEO features with new plugins and metadata

- Introduced rehypeLazyImages plugin for lazy loading images in blog posts.
- Updated sitemap integration to include last modified dates for blog posts.
- Enhanced Head and BaseLayout components to support additional Open Graph metadata.
- Improved RSS feed generation with sanitized content and author information.
- Updated manifest.json for a darker theme and standalone display mode.
- Added support for language-specific attributes in various components.
- Refactored blog post handling to include modified and published timestamps.

package.json

@@ -32,14 +32,18 @@
     "geist": "^1.4.2",
     "globby": "^16.0.0",
     "gray-matter": "^4.0.3",
+    "markdown-it": "^14.1.1",
     "mdast-util-to-string": "^4.0.0",
     "reading-time": "^1.5.0",
+    "rehype-external-links": "^3.0.0",
+    "sanitize-html": "^2.17.3",
     "sass": "^1.89.1",
     "satori": "^0.26.0",
     "satori-html": "^0.3.2",
     "schema-dts": "^2.0.0",
     "sharp": "^0.34.2",
-    "typescript": "^5"
+    "typescript": "^5",
+    "unist-util-visit": "^5.1.0"
   },
   "devDependencies": {
     "prettier": "^3.5.3",