Merge requests are a place to propose changes you've made to a project and discuss those changes with others
Interested parties can even contribute by pushing commits if they want to.
How to register an account on GitLab. To prevent spam, new accounts are locked until approved by an admin or the approver bot. You can also file an unlock request to expedite access.
Support: mw:GitLab, how to host a project on GitLab, #wikimedia-gitlab on libera.chat, #GitLab on Phabricator.
Interested parties can even contribute by pushing commits if they want to.