Updated shuffle_swatch() method for new ggthemr class layout.
Removed reverse_swatch().
Introduced verify_ggthemr() method.
Updated methods to change swatch.
Updated colour contrast methods.
Created random_swatch_colour() function.
Removed some empty colours from sky theme.
Working define_palette() method.
Updated define_palette() documentation.
Improved the define_palette() documentation.