doc: squash commits in contrib guide
@@ -65,6 +65,7 @@ Due to legal reasons, contributors will be asked to accept a Developer Certifica
1. Set respective comments in your GitHub review to resolved.
1. Create a general PR comment to notify the reviewers that your amendments are ready for another round of review.
+1. When merging into main, make sure that all commits belonging to a pull-request get squashed into one single commit that gets merged.
## Issues and Planning
