Wikis typically connote distributed, anonymous edits. This feature is partially covered by git already.

The linked URL to the home page there can even serve as an example: the "trunk" is a check-in name (https://fossil-scm.org/home/doc/trunk/www/checkin_names.wiki) that points to the newest check-in on the "trunk" branch. You can replace it with any other reference to get the old version; eg, version-2.20 would work to get the version 2.20 of the docs, 2015-03-14 would work to get the version from 14 March 2015, etc.

In that case, when the docs are not associated with a code change, you want to make getting those improvements into the docs as frictionless as possible, otherwise the changes aren't going to get made.

Personally, I've found that making docs updates incredibly fast + easy to be far more valuable than anything you get from forcing doc changes through the full SDLC process. If someone has feedback on your docs changes they would have shared in a review, they can just update the docs instead.

however I think maybe this has changed? I don't see it in https://github.com/robots.txt now