[mattgibson]

Currently, after trying quite a few other things (Basecamp, Confluence, READMEs, just not bothering to document things), we've now settled on using a simple git repo of markdown pages which auto deploys to a mkdocs site from master.

We have this set up to require merge requests on GitLab to be approved by two developers and for each new merge request to appear on Slack via a webhook when it's opened.

This has been extremely effective because we now have:

  - History via git (better than a simple wiki)  
  - Simple diffs because markdown
  - Immediate visibility of upcoming changes via Slack
  - At least two other developers forced to actually read the new page(s) before they are added
  - Nice HTML/CSS via the material mkdocs theme, which we can easily customise

Using tools that are already familiar to the team has been a big win. People are enthusiastic about this solution in a way that they never were about the others.