Add CSS4() and JSON() methods to Palette.

[dayvonjersen]

• coming back to this project after 7 (SEVEN) years! what a rush!
• some background: I originally made this port from Java so I could use it in the production of another project that has been one false start after the next since 2009. I'm back on my BS and trying it one more time™ anyway after having to use this library in my own code I realized it wasnt' outputting what I want/needed to use it. I needed JSON to store it in the DB, CSS4 vars to use in the UI and 16 bit colors as integers to do image fills with the image package in stdlib
• this comes up short of an ideal solution however and isn't as flexible as it should be yet but it's one small step in that direction
• feedback and contributions welcome!!!
• happy hacking, -Dave, from NJ Sun 11 Jun 2023 11:24:03 PM EDT

https://pbs.twimg.com/media/FyZD6d3XgAAVBKz?format=jpg&name=large <- screenshot of it working, can I post images on github why not

[dayvonjersen]

I didn't check if ExtractAwesome() re-runs the algorithm that finds the swatches every time if so this could get very expensive indeed should refactor to cache the result once and render as JSON, CSS, CSV, or whatever else people might want
-day

[dayvonjersen]

I knew there was a reason to check the diff. Have to add a go.mod file or merge #4