1) Make a convention to keep something like
docs dir in each of your git repos that contains buildable adoc documentation.
2) Create a Jenkins pipeline that clones your repositories, builds the adoc files, and serves a web index page that you can browse.
3) Execute the pipeline periodically, e.g. once a day.
There, you've got a docs system that is:
- Dev friendly, because they can write docs from their IDEs
- Centralized
- Restricted to whoever has access to Jenkins. So if you put Jenkins behind a VPN, it'll be accessible only there.
I'm sure you can tweak it to give access to some folks to only some pages, though I haven't done that.