rc file-detection hook group
rc file-detection hook group

Add a group to the `file-detection` hooks.

There's no way to remove hooks without a group. With this patch, you'll be able to remove those
`file-detection` hooks manually. There's no need for two separate groups since if you wanted to
remove only one, you could run `remove-hooks` and then only add one again.


Related: #3670
casimir/kakoune,mawww/kakoune,casimir/kakoune,jkonecny12/kakoune,mawww/kakoune,casimir/kakoune,jkonecny12/kakoune,jkonecny12/kakoune,jkonecny12/kakoune,mawww/kakoune,mawww/kakoune,casimir/kakoune