We've used HackMD in my OSS project since Google Docs was failing us as far as version control goes. What's great is that you can sync a HackMD document to GitH

We've used HackMD in my OSS project since Google Docs was failing us as far as version control goes. What's great is that you can sync a HackMD document to GitHub or similar, so you can collaborate on a document and then push it to a repo.