Add the remainder of the To Do Items

[SirGoodenough]

Did some work to complete the rest of the To Do list documented in the first releases.
All these items have now been completed:
# 🦠 TO-DO List

  - Push to HACS Custom.
  - Error checking inputs for range.
  - Return a list of all the official color names.
  - Clean-up code, add shortcuts on redundancies.
  - Add ```Display closest color name to a given RGB```
  - Push to HACS released.