restore YAML frontmatter

package.json

@@ -40,8 +40,6 @@
     "modern-normalize": "^3.0.1",
     "next": "15.3.0-canary.10",
     "obj-str": "^1.1.0",
-    "p-map": "^7.0.3",
-    "p-memoize": "^7.1.1",
     "polished": "^4.3.1",
     "prop-types": "^15.8.1",
     "react": "19.0.0",
@@ -58,7 +56,9 @@
     "rehype-slug": "^6.0.0",
     "rehype-stringify": "^10.0.1",
     "rehype-unwrap-images": "^1.0.0",
+    "remark-frontmatter": "^5.0.0",
     "remark-gfm": "^4.0.1",
+    "remark-mdx-frontmatter": "^5.0.0",
     "remark-parse": "^11.0.0",
     "remark-rehype": "^11.1.1",
     "remark-smartypants": "^3.0.2",