Update merge request workflow contribution docs

doc/development/contributing/merge_request_workflow.md

@@ -68,10 +68,11 @@ request is as follows:
    1. Use the syntax `Solves #XXX`, `Closes #XXX`, or `Refs #XXX` to mention the issue(s) your merge
       request addresses. Referenced issues do not [close automatically](../../user/project/issues/managing_issues.md#closing-issues-automatically).
       You must close them manually once the merge request is merged.
+   1. The MR must include *Before* and *After* screenshots if UI changes are made.
+   1. Include any steps or setup required to ensure reviewers can view the changes you've made (e.g. include any information about feature flags).     
 1. If you're allowed to, set a relevant milestone and [labels](issue_workflow.md).
 1. UI changes should use available components from the GitLab Design System,
-   [Pajamas](https://design.gitlab.com/). The MR must include *Before* and
-   *After* screenshots.
+   [Pajamas](https://design.gitlab.com/).
 1. If the MR changes CSS classes, please include the list of affected pages, which
    can be found by running `grep css-class ./app -R`.
 1. If your MR touches code that executes shell commands, reads or opens files, or