Docs feedback - feature proposal (code review): support for comments on the file level
### Problem to solve
<!--- What problem do we solve? -->
During code reviews a possibility to add some information on the file level. If some file is renamed, it is not possible to add any comment to it.
### Further details
My colleague renamed a file and had a double extension (e.g. file1.json.json). Right now it is not possible to add a comment during code review to the file without changes (also not on the file level). So I had to use less specific general merge request discussion.
Another use cases:
* file becomes obsolete and should be removed altogether (so the comment is not related to any line in the file)
* file should be moved or renamed
### Proposal
Add possibility to submit a comment for the file (e.g. a renamed one, which was renamed incorrectly).
### What does success look like, and how can we measure that?
Comment appears not for some specific line, but for the whole file.
### Links / references
issue