## Summary of the Pull Request
This PR performs a number of miscellaneous clean-up tasks on our schema:
- [X] allow null for some settings
- [X] update some default values to be more useful
- [X] consistently use " instead of '
- [X] remove colorTable
- [X] provide missing description for `backgroundImageOpacity`
- [X] update cursorShape to have options match order displayed in vs code
- [X] if a setting has multiple options, provide a list of those options with a short description on each
- this one I only did a few times
- [X] remove a little bit of ambiguity on some descriptions
## PR Checklist
Closes#5279
## Detailed Description of the Pull Request / Additional comments
Validation was performed for...
- [X] Global Settings
- [X] Profile Settings
- [x] Keybinding Actions
## Validation Steps Performed
I linked VS Code to the my version of the schema. Defined all settings from scratch in settings.json. Anytime I found something off, I updated the schema and saw if it looks right.
9e23ee7fd6