Added commands to transfer the group namespace.

doc/administration/troubleshooting/gitlab_rails_cheat_sheet.md

@@ -484,6 +484,16 @@ user.max_member_access_for_group group.id
 
 ## Groups
 
+### Transfer group to another location
+
+```ruby
+user = User.find_by_username('<username>')
+group = Group.find_by_name("<group_name>")
+parent_group = Group.find_by(id: "") # empty string amounts to root as parent
+service = ::Groups::TransferService.new(group, user)
+service.execute(parent_group)
+```
+
 ### Count unique users in a group and sub-groups
 
 ```ruby