[DOCS] Add Rules and module documentation

[davidhawbecker]

You state "this module was created with my table's homebrew rules in mind". So where is the rule set? The tracker looks nice on the character sheet, but I can't find any other references or documentation. I've check the module settings and compendiums.

[deadpyxel]

I have been working on the companion documentation, it should be up soon in both the project readme and Github pages. I'll set this as a higher priority item for next release (v0.7.1)