New egg: web-colors

[John Croisant]

I have published a new egg, web-colors. It provides procedures to parse
and write colors in a variety of formats used in HTML/CSS:

- Hex colors in #RGB, #RGBA, #RRGGBB, and #RRGGBBAA formats
- rgb() and rgba() colors
- hsl() and hsla() colors
- Named colors, a.k.a. color keywords

The egg is mainly targeted at CHICKEN 5, but also works with CHICKEN 4.
There can sometimes be differences in the exactness of numbers due to
CHICKEN 4 not having a built-in ratio type.

Docs: https://wiki.call-cc.org/eggref/5/web-colors

Release info for CHICKEN 4 and 5:
https://gitlab.com/jcroisant/chicken-web-colors/raw/master/web-colors.release-info

Happy new year!

- John Croisant