Support frontmatter

[jacobdalamb]

Check for existing issues

• Completed

Describe the feature

Frontmatter is a section at the beginning of a file that contains metadata about the file or the document. It's often used in static site generators such as Astro. The information is written in YAML, JSON, or TOML format and is enclosed between a set of triple-dashed lines (--- or +++). The metadata within can include properties such as title, date, layout, categories, etc.

---
title: "My Blog Post"
date: 2021-01-31
---

In this example, "title" and "date" are metadata fields contained within the frontmatter. The information in the frontmatter can be used to generate webpages, sort posts, create navigations, among other uses.

Static site generators which use frontmatter in Markdown files:

• jekyll
• hugo
• zola
• pandoc
• docusaurus
• markdoc
• middleman
• aettlr

If applicable, add mockups / screenshots to help present your vision of the feature

No response

[alvgaona]

For Astro, it's been added in #6896

[jacobdalamb]

Yeah I'm talking about markdown support for it

[andreacfromtheapp]

+1 with a note: please support both YAML (---) and TOML (+++) frontmatter

[notpeter]

Thanks for the heads up @andreacfromtheapp I've updated PR #21503 to correctly support this.