[`coq/bot`] Track issues encountered since using this bot

[myii]

There have been a variety of problems encountered since using the bot. This issue is a catch-all for the issues that have been reported:

• Does not work for repos using GitLab subgroups (i.e. only works for owner/name) rocq-prover/bot#120
• Removing (and changing?) the coqbot.toml does not work without intervention rocq-prover/bot#121
• Enable "Post comment when a pull request does not respect certain standards" for other coqbot users rocq-prover/bot#123
• GitLab subgroups fix for #120 still needs some finalisation rocq-prover/bot#124
• coqbot starts creating empty, unconfigured repositories rocq-prover/bot#127