Mention when "/commits/:sha/merge_requests/" endpoint was introduced

doc/api/commits.md

@@ -539,6 +539,8 @@ Example response:
 
 ## List Merge Requests associated with a commit
 
+> [Introduced][ce-18004] in GitLab 10.7.
+
 Get a list of Merge Requests related to the specified commit.
 
 ```
@@ -608,3 +610,4 @@ Example response:
 [ce-6096]: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6096 "Multi-file commit"
 [ce-8047]: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/8047
 [ce-15026]: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/15026
+[ce-18004]: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/18004