tools: added remark-frontmatter

remark-frontmatter allows the use of frontmatter metadata in markdown
files

PR-URL: #38717
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Daijiro Wachi <daijiro.wachi@gmail.com>
Reviewed-By: Derek Lewis <DerekNonGeneric@inf.is>

tools/doc/generate.mjs

@@ -27,6 +27,7 @@ import htmlStringify from 'rehype-stringify';
 import gfm from 'remark-gfm';
 import markdown from 'remark-parse';
 import remark2rehype from 'remark-rehype';
+import frontmatter from 'remark-frontmatter';
 import unified from 'unified';
 
 import * as html from './html.mjs';
@@ -82,6 +83,7 @@ async function main() {
   const input = await fs.readFile(filename, 'utf8');
 
   const content = await unified()
+    .use(frontmatter)
     .use(replaceLinks, { filename, linksMapper })
     .use(markdown)
     .use(gfm)

tools/doc/package.json

@@ -11,6 +11,7 @@
     "js-yaml": "4.1.0",
     "rehype-raw": "5.1.0",
     "rehype-stringify": "8.0.0",
+    "remark-frontmatter": "^3.0.0",
     "remark-gfm": "^1.0.0",
     "remark-html": "13.0.1",
     "remark-parse": "^9.0.0",