Why highlight mermaid need the ````mermaid` to start

[litingyes]

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Describe the bug

Why do we need to add ```mermaid to highlight mermaid codes?

Reproduction

https://textmate-grammars-themes.netlify.app/?theme=catppuccin-latte&grammar=mermaid

Contributes

• I am willing to submit a PR to fix this issue
• I am willing to submit a PR with failing tests

[quilicicf]

I'm surprised too, I worked around it by adding the fences then removing them with a transformer but that's not ideal.

Why does it look like Mermaid is the only language that's assumed to be part of a Markdown document ?

[slevithan]

Looks like shikijs/textmate-grammars-themes#131 is a proposed fix for this.