Add palette of the XKCD color survey

[m-haug]

No description provided.

[kaarmu]

Thanks! I just have one suggestion, I'd like the color names to be kebab-case so it is natural to access them as fields.

[m-haug]

I've changed most colour names to use kebap-case. The only exception is colours which contain slashes (blue/green) because often the two obvious alternatives (bluegreen and blue-green) are also already part of the dataset.

[kaarmu]

Thanks!