Add docs on Stuff that should Just Work label

doc/development/contributing/merge_request_workflow.md

@@ -248,3 +248,16 @@ request:
 1. The [GitLab Development Kit](https://gitlab.com/gitlab-org/gitlab-development-kit).
 1. The [CI environment preparation](https://gitlab.com/gitlab-org/gitlab/blob/master/scripts/prepare_build.sh).
 1. The [Omnibus package creator](https://gitlab.com/gitlab-org/omnibus-gitlab).
+
+### Incremental improvements
+
+We allow engineering time to fix small problems (with or without an
+issue) that are incremental improvements, such as:
+
+1. Unprioritized bug fixes (e.g. [Banner alerting of project move is
+showing up everywhere](https://gitlab.com/gitlab-org/gitlab/merge_requests/18985))
+1. Documentation improvements
+1. Rubocop or Code Quality improvements
+
+Tag a merge request with ~"Stuff that should Just Work" to track work in
+this area.