Overhaul for 3.0

[haggen]

• Check current features.
• Write down what stays and what'll be cut out.
• Rewrite.

References:

Sheet and formula for XP to next CP level:

• https://forums.elderscrollsonline.com/en/discussion/222867/champion-system-catch-up-mechanic/p1
• https://docs.google.com/spreadsheets/d/1iX6kRm9nkstp0R6hE_Pr3Tw69GHCtkOp68llHUeoZ_M/edit#gid=428639707