YAML frontmatter hyphens in markdown files are incorrectly scoped/have no scope applied

[Fantazstic]

Does this issue occur when all extensions are disabled?: Yes

• VS Code Version: 1.74.2
• OS Version: Windows 10 Pro 64bit 20H2

Steps to Reproduce:

1. Create feature_request.md:

---
name: Feature request
about: Suggest an idea for this project
title: "[REQUEST]"
labels: enhancement
assignees: ''

---

**Is your feature request related to a problem? Please describe.**
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**Describe the solution you'd like**
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**Describe alternatives you've considered**
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**Additional context**
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2. Use "Developer: Inspect Editor Tokens and Scopes"
3. Select the frontmatter hyphens ---
4. Notice empty scope/no scope applied
5. So, we can't edit the colors (cannot use text.html.markdown since that will select all the normal text too)

[mjbvz]

YAML front matter is not a standard markdown concept. For core VS Code, we target standard common mark but support for additional features can be contributed by extensions

[Fantazstic]

@mjbvz Thanks for the reply.

It looks like VSCode can recognize horizontal rule common markdown, but only further down in the file.

AFAIK other editors, for example Atom, have consistent syntax highlighting, while VSCode is being inconsistent with them.

Screenshots:

VSCode	Atom

Could we get support for the untokenized separators to be tokenized as meta.separator.markdown as well?