Markdown vaildation throws error at footnotes

[LangLangBart]

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

• VS Code Version: `1.74.2
• OS Version: macOS 10.15

Steps to Reproduce

1. Enable markdown validation

"markdown.validate.enabled": true

2. Create a .md file in VSCode and write a footnote, for example:

- footnote1[^1]
- footnote2[^2]

[^1]: Text1
[^2]: Text2

3. Errors are reported

No link definition found: '^1'(link.no-such-reference)
No link definition found: '^2'(link.no-such-reference)

Expected behavior

• VSCode recognizes the footnote and does not trigger an error.

[LangLangBart]

It has already been reported in another repository, I will close this ticket here.

microsoft/vscode-markdown-languageservice#100