Revert changes by reverting a commit

**Is your feature request related to a problem? Please describe.**
A big advantage of netlify cms over other CMS's is the git backend. There's no easy way to undo changes (a.k.a. revert commit)

**Describe the solution you'd like**
Ideally we could have a list of all commits and you could click where do you want to revert.

**Describe alternatives you've considered**
This feature is kinda duplicate of github, bitbucket, git cli etc. But those tools are not for "bloggers" - netlify cms is!

**Additional context**