README: contributing
major rewrite for mineos 0.6

Basically a rewrite from scratch.
Merge branch 'feature/mineos-0.6' into develop

Conflicts:
	README.md
updated README
removed `force_deploy` action
updated changelog
fixed group creation; now existing users will not be kicked
changed [mineos][config][ssl][enable] to a proper boolean
Merge branch 'release/v2.0.0'