Currently, we agreed on the following development workflow:
1. New major changes go to a separate branch.
2. A PR should be opened as draft until it's ready for review.
3. When it's ready, remove the draft status and assign a reviewer.
4. When an agreement is achieved, the PR's author merges the PR. GH's "rebase and merge" button is preferred, but in some special cases it's OK to use "create a merge commit" option.