feat: code block highlighting

[Sembauke]

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• I have read freeCodeCamp's contribution guidelines.
• My pull request has a descriptive title (not a vague title like Update index.md)

Closes #387

[socket-security]

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Package	New capabilities	Transitives	Size	Publisher
npm/@tiptap/[email protected]	Transitive: environment, filesystem	+49	7.51 MB	_bdbch
npm/[email protected]	None	+5	4.04 MB	wooorm

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[sidemt]

The code block is working fine, but now the inline code block is showing backticks around it (which you have fixed in PR #203)

If it's difficult to handle both inline code and multi-line code blocks with a single button, it's ok to add a selectbox to choose either inline code or code block.

Edit: I think I found how to fix it. It was a bit complicated to add as suggestions so I will open a separate PR later. Other changes LGTM 👍

I will open another PR