Clean up Readme some more

Information section may be wrong, removing for now as it's probably not needed.  If I need it in the future, I'll just re-add.

Changed wording on contributing from "Dev" branch to "master" as I don't currently have a Dev branch :3
Add Modpack Description to Readme

To give people an idea of what to expect when they visit the repo.
_ITALICS_

_Because EMPHASIS_
Re-add CoroUtils

Accidental removal due to zip file derp.