Remove findInFiles js-api danger note

[sseppola]

This was fixed almost a year ago according to the PR ast-grep/ast-grep#206 (comment)

[HerringtonDarkholme]

Hi, thanks for the pull request.
However, the napi limitation was not fixed. We found the issue one year ago but it was still there due to nodejs' implementation.

So I do think the section should be kept.

But thanks for the pull request anyway!

[sseppola]

Aha, then I misunderstood what was fixed!
I was going to report it as an issue, but figured I may as well make the change instead.

Thanks for making such a cool tool! I appreciate the effort of making ASTs more approachable 🙌