Add colorblindness simulator to colourPicker

Hi,

Thanks for the great package – it spares me the time it takes to constantly look up R native colors and compare them with trial and error!

One thing that I see missing is a color vision deficiency simulator (like @clairemcwhite and @clauswilke's `colorblindr` [package](https://github.com/clauswilke/colorblindr)). Currently, I save my chosen color palette in a png file and use online tools ([like this](http://hclwizard.org:3000/cvdemulator/)) to check whether my palette is print- and colorblind-friendly.

It would be great if you could add (three) more rows underneath the selected colors that would show how it is seen by people with protanomaly (2% of males), deuteranomaly (6% of males), tritanomaly, and desaturated (that would simulate grayscale printing) vision deficiency. Here's what I mean (poorly made in Paint 😄):


In case it feels like too much information overload and only one should be chosen, I believe the desaturated one (grayscale) is the most relevant since it is black-and-white print-safe and also safe for all other types of color vision deficiencies.