Missing breaking change notice in update documentation

Problem to solve

The documentation concerning Gitlab update miss important information about changes brought by a new version.

Further details

I recently updated my self-hosted instance to v12.1 and I was surprised my Merge Request pipelines failed. I had to dig into the documentation to finally find this page stating that

Pipelines for merge requests are incompatible with CI/CD for external repositories.

I use CI/CD for external repositories. If I had been informed that updating would break my CI, maybe I would have taken my time to think about it. It is very unpleasant to discover this afterwards.

Proposal

Please document this kind of breaking changes in the future.

Who can address the issue

Other links/references