@lumirlumir I think this is the rule you wanted to work on?

Thanks for mentioning me, @Pixel998. I mentioned this rule in another comment, but I didn’t raise an issue about it—so I’m fine with whoever decides to take it on.

It’s a good rule to implement, especially since it’s already covered in markdownlint.

That said, please keep in mind that this rule could be tricky to implement due to potential edge cases, since ##heading is recognized as a normal text node (Maybe it could be another node too).

I’m in favor of creating this rule, but I’d like to hear what the rest of the team thinks before moving forward. @eslint/eslint-team

Also, the name of this rule should be shortened, it's a bit too long to be practical as a rule name.

I recommend to use no-missing-space-atx or similar. This name was used in markdownlint.

I will pick this up and submit a PR

👍🏻 for no-missing-space-atx, I think we should also have this as a recommendation.