Support Quarto Markdown format extensions

[XVilka]

Check for existing issues

• Completed

Describe the feature

Quarto is a popular publishing software with an input format being Markdown with a few extensions, for example, https://quarto.org/docs/authoring/markdown-basics.html#callout-blocks

It also usually uses *.qmd file extension.

Supporting these syntax extensions properly would make use of Vale with Quarto files much nicer.

See also:

• https://quarto.org/docs/authoring/language.html
• https://quarto.org/docs/authoring/article-layout.html
• https://quarto.org/docs/authoring/front-matter.html
• https://quarto.org/docs/authoring/footnotes-and-citations.html
• https://quarto.org/docs/authoring/cross-references.html
• https://quarto.org/docs/authoring/cross-references-divs.html
• https://quarto.org/docs/authoring/appendices.html
• https://quarto.org/docs/blog/posts/2024-01-24-1.4-release/#inline-code-syntax