Cannot associate review comments with highlighted fragments of code
[Gerrit has a really nice feature where you can select a fragment of code with which to associate your review comment.](https://gerrit-review.googlesource.com/Documentation/user-review-ui.html#add-inline-comment)
In contrast, GitLab only allows you to associate your comment with (the whole of) a single line. This means:
- you can't clearly comment on a fragment of a line, which would be especially useful if you want to comment separately on multiple fragments within a line, and
- ~~you can't comment on multiple lines.~~ (**UPDATE:** this one is no longer true)
### Proposal
Copy Gerrit's behaviour.
### Links / references
[GitHub has the same feature gap](https://github.com/isaacs/github/issues/1208), so this is another opportunity to be better than GitHub :-)
issue