Additional Skills, Determination and Moxie as DerivedData?

[tyhayescreative]

i.e. in game.dnd5e.entities.Actor5e.prototype.prepareDerivedData()

I think the derivedData doesn't save into the database but is calculated at render time.

May be issues with timing

• moxie needs the skill modifiers to be initialised, which happens in the system derived data function
• check whether feats that give bonuses to the new data still work properly.

[tyhayescreative]

skills should probably actually be added in _prepareBaseSkills