fix issue with front-matter being rendered

Author: jderochervlk

AGENTS.md

@@ -64,6 +64,9 @@ __tests__/        → Vitest browser-mode tests (Playwright)
 - Output format is ES modules with `.jsx` suffix, compiled in-source (`.jsx` files sit alongside `.res` files).
 - Reference the abridged documentation for clarification on how ReScript's APIs work: https://rescript-lang.org/llms/manual/llm-small.txt
 - If you need more information you can access the full documentation, but do this only when needed as the docs are very large: https://rescript-lang.org/llms/manual/llm-full.txt
+- Never use `%raw` unless you are specifically asked to
+- Never use `Object.magic`
+- Don't add type annotations unless necessary for clarity or to resolve an error. ReScript's type inference is powerful, and often explicit annotations are not needed.
 
 ### ReScript Dependencies
 

src/common/MarkdownParser.res

@@ -27,6 +27,15 @@ type result = {
 
 let vfileMatterPlugin = makePlugin(_options => (_tree, vfile) => vfileMatter(vfile))
 
+type remarkNode = {@as("type") type_: string}
+type remarkTree = {mutable children: array<remarkNode>}
+
+let stripFrontmatterPlugin = makePlugin(_options =>
+  (tree, _vfile) => {
+    tree.children = tree.children->Array.filter(node => node.type_ !== "yaml")
+  }
+)
+
 let parser =
   make()
   ->use(remarkParse)
@@ -35,6 +44,7 @@ let parser =
   ->use(remarkComment)
   ->useOptions(remarkFrontmatter, [{"type": "yaml", "marker": "-"}])
   ->use(vfileMatterPlugin)
+  ->use(stripFrontmatterPlugin)
 
 let parseSync = content => {
   let vfile = parser->processSync(content)