tools: added remark-frontmatter

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

PR-URL: https://github.com/nodejs/node/pull/38717


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