Self-host GitLab server support

[sheiun]

Hope it can support custom domain.

[veod32]

https://hackmd.io/s/hackmd-it-release-notes#v0422019-11-11
It's not really clear from the description how to work with and manage this option. And it's also not clear what I can and cannot do regarding using HackMD-it vs. gitlab.com projects. Can you please elaborate?

[sheiun]

I want to use it on my self-host gitlab server (domain is not gitlab.com), that I hope it can add a button "Edit on HackMD" like official gitlab.