I second the needing a single, searchable source of truth. One of the main needs is for it to be maintained and updated. Having it all in one place helps with t

I second the needing a single, searchable source of truth. One of the main needs is for it to be maintained and updated. Having it all in one place helps with that and reduces the cognitive load of making the decision of where to update. We use fossil; a bit minimalistic, but you get a wiki + code repository + tech notes + issue tracking all in one place and auto-updated with the code, and you can run it as a server with a web interface for those who don't need permissions to clone the repo.