initial commit, all colors/modifiers fleshed out
name changes, added Stylize functions

I changed the CSI variable to not be exported because there is
no reason for it to exported. The Style type has been added to
semi-enforce (aka, suggest) that only the package variables should
be used when using Stylize.

I also added the Stylize function, which prepends styles
to a text string, adds the Reset code at the end and returns the string
added API documentation for how stylize works
added a SavedStylize function and relevant map
renamed package to stylize and moved documentation
Merge branch 'master' of https://github.com/twmb/stylize