Sample Points Dialog: Update to 2.99
- Add missing dropdown options in Sample points dialog.
- Remove outdated info that Sample points dialog only displays four sample points.
- Make example image also display existing sample points.
- Remove non-sensical stuff ("by default" when there is no non-default; "should open" but "This is not the case").
- Use consistent terminology across docs: "status area" not "information bar", "ruler" not "rule", "Color Picker" not "Eye Dropper".
- Link to docs about Color Picker tool and to explanation of "a paint tool".
- Remove self-explanatory and trivial screenshot of a menu with a single entry.
- Update Sample points dialog screenshot.