Documentation for File Lock feature

doc/workflow/README.md

@@ -8,6 +8,7 @@
 - [Importing to GitLab](doc/importing/README.md)
 - [Keyboard shortcuts](shortcuts.md)
 - [File finder](file_finder.md)
+- [File lock](file_lock.md)
 - [Labels](labels.md)
 - [Issue weight](issue_weight.md)
 - [Manage large binaries with git annex](git_annex.md)

doc/workflow/file_lock.md

+# File Lock
+
+>**Note:**
+This feature was [introduced][ee-440] in GitLab 8.9.
+
+---
+
+GitLab enables us to lock any file or path in repository tree. If you have a lock
+then you are the only one who can push changes to the repository where locked objects are changed.
+Locks can be created by any person who has access to push the code; i.e., developer and higher level.
+The user with master permissions level can remove any lock, no matter who is the author of the lock.
+
+## Locking
+
+To lock any file or folder open it in GitLab Code viewer and you will see appropriate link or button
+
+![Locking file](file_lock/file_lock.png)
+
+![Locking folder](file_lock/folder_lock.png)
+
+
+---
+
+## Viewing/Managing existing locks
+
+To view or manage every existing lock go to the **Project > Code > Locked Files** section.
+
+![ocked Files](file_lock/locked_files.png)
+
+---
+## License note
+
+To activate this feature you have to have a license with the "File Lock" option enabled.
+
+---
+
+[ee-440]: https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/440 "File Lock"