I know this is pretty much what the wiki is for, but would there be any possibility of adding a docs repo under the Unreal organisation?
Doing it this way lets the community contribute to the documentation and any changes will only be pushed into the live docs after being validated and pulled by a verified contributor.
The documentation pages can also be written to pull in data directly from the github repo, so any changes that are made in the repo will immediately show up on the documentation page.
Having it in a repo would also let the community post issues about certain parts of the docs that might seem either too vague or hard to understand, and suggest better ways of phrasing it.
I know this would be a huge overhaul of the current docs system, but just something to consider for the future.