I recently contributed to a repository that had a well established CHANGELOG, Migration Guide and README.

The circumstances of the contribution arose from an urgent need for a fix that was impacting multiple consumers, so I was in a rush and had a tight deadline, but I took the extra few moments to update all three documents because they existed and were so well maintained, I wasn’t going to be the one who cut corners and ruined it.

Broken Window Theory in play here, of sorts — if you maintain good, precise documentation, contributors to your repository are more likely to contribute to that documentation too.

A great experience, and one I hope repository maintainers will make the norm.