Rules engine

A base rules framework that reads in rulesets defined in JSON files.

The new character generation pulls in these rules to define what is available.

Right now everything pretty much just has a "name" field that has the UI-presentable value, but could be extended to include other attributes like maybe class attributes, racial bonuses, etc.
I like that the rules logic is separate. we could easily turn this into a template to make custom rules logic to call into at certain points (this might be where special abilities for items go, etc)