abstract branding

[clif-os]

• adds readme for customizing coloring and branding images
• abstract css colors to a single css file
• use fostive branding

[superhighfives]

This is awesome, @clif-os! I think it'd be great to add a little more context to the branding readme, (heading, links to GitHub, an explanation of what can be branded followed by the details for each). cc @justjenu

[clif-os]

@superhighfives that sounds good. what do u mean by github links sorry?

[superhighfives]

Was thinking links to the different aspects of the GitHub repo / back to the FOSTIVE org, but can ignore @clif-os as @DianaPerkinsDesign is going to help out with this one. Thanks! 🙌