#Anki quick colors

Adds keyboard shortcuts Ctrl+Shift+num which change the selected editor colour to the custom color with that index in the color picker, and apply that color to any highlighted text.

Similar to the existing addon Quick Color Changing, but requires no configuration by using the inbuilt custom color selection.

Note that the 'Custom colors' boxes index vertically rather than horizontally, as seen in the screenshot below. This is not to do with my code, it's just how the inbuilt color picker works internally.