Add support for background-clip & prepare for multilayered backgrounds!

Add test script!

Implement background-colour rendering!

Draft background-colour shader.

Parse background-colour CSS property.

Integrate colour parsing & add accent-colour support.

accent-colour takes no effort & helps (custom) form controls clash less with webpages.

Parse CSS colour hexcodes & keywords.

Start parsing CSS colours!

Add scaffolding for CSS property parsing.

Prepare canvas on which to code.