Update Approval Rule documentation
Approval Rule documentation needs to be updated to reflect existing behavior, specifically these two examples
- If approvals overriding is disabled, changing the project approval rules changes all existing MRs.
- If approvals overriding is enabled, changing the project approval rules does not change any of the existing MRs, regardless if those MRs have overridden the project rules or not.
- Furthermore, if I override an MRs approval rules and then disable overriding, the overridden MR assumes the project approval rules. But if I then enable overriding again, the MR recovers the rules that I had overridden, and is back to how it was before overriding was disabled.
changing an approval rule's target branch affects existing merge requests when overriding approval rules is enabled, which is a different behavior from all of the other approval rule fields.