Docs for `merge_requests_author_approval` seem to be backwards

Problem to solve

I think there are a couple of issues in the https://docs.gitlab.com/ee/api/merge_request_approvals.html docs.

1. The disable_overriding_approvers_per_merge_request, merge_requests_author_approval, and merge_requests_disable_committers_approval keys are not shown in the GET docs, but they do seem to be part of the response.
2. The true/false sense of the merge_requests_author_approval value seems to be backwards - when I have the "Prevent approval of merge requests by merge request author" option selected in my project's configuration, I get the value false here in the API response. The documentation seems to say the opposite: "Allow/Disallow authors from self approving merge requests; true means authors cannot self approve". I believe this is a documentation error, not an API code bug, but there are multiple negatives ("cannot" and "prevent" and "disallow" etc.) that make this kind of hard to understand.

Proposal

Change the doc text "Allow/Disallow authors from self approving merge requests; true means authors cannot self approve" to "Allow/Disallow authors from self approving merge requests; false means authors cannot self approve".