Fix documentation for Accessibility settings
This MR:
- fixes existing documentation issues
- does some light formatting
- documents the new UI changes done in !2422 (merged), such as Activation Gestures -> Activation Shortcuts
- documents the new Color Blindness correction !2472 (merged)
- documents the new Shake Cursor !2083 (merged)
Do not review this before it is marked as Ready. This is ready to review.
I'm aware of some missing Docbook formatting issues.
Edited by Thiago Sueto