Why collaboration markdown editor with offline sync?

I was using QUIP for document before. However, it doesn't good for markdown user. My team and I are using markdown for API document for projects. We want to update the markdown document in real time. We found usecanvas.com . It really great. But it don't have the important feature like label or folder. I would like to get QUIP with canvas editor. Is there any other markdown editor better than usercanvas.com ? https://my-accountaccess.com/