Merge branch 'osw-comment-on-any-diff-line-docs' into 'master'

Add docs for commenting in any line of MR diff files

See merge request gitlab-org/gitlab-ce!22878

(cherry picked from commit fad88129f4aacda44b011a2404b0a53049d6212d)

19a79483 Add docs for commenting in any line of MR diff files

2 files changed, 9 insertions, 0 deletions

diff --git a/doc/user/project/merge_requests/img/comment-on-any-diff-line.png b/doc/user/project/merge_requests/img/comment-on-any-diff-line.png
new file mode 100644
index 00000000000..856ede41527
--- /dev/null
+++ b/doc/user/project/merge_requests/img/comment-on-any-diff-line.png
diff --git a/doc/user/project/merge_requests/index.md b/doc/user/project/merge_requests/index.md
index 6de2ab07fc4..f2f2497f0be 100644
--- a/doc/user/project/merge_requests/index.md
+++ b/doc/user/project/merge_requests/index.md
@@ -141,6 +141,15 @@ you hide discussions that are no longer relevant.
 
 [Read more about resolving discussion comments in merge requests reviews.](../../discussions/index.md)
 
+## Commenting on any file line in merge requests
+
+> [Introduced](https://gitlab.com/gitlab-org/gitlab-ce/issues/13950) in GitLab 11.5.
+
+GitLab provides a way of leaving comments in any part of the file being changed
+in a Merge Request. To do so, click the **...** button in the gutter of the Merge Request diff UI to expand the diff lines and leave a comment, just as you would for a changed line.
+
+![Comment on any diff file line](img/comment-on-any-diff-line.png)
+
 ## Resolve conflicts
 
 When a merge request has conflicts, GitLab may provide the option to resolve