Offer HDR palettes with the same import names as the original hex palettes

[argyleink]

used like @import "open-props/indigo-p3"; or @import "open-props/indigo-oklch";

• display p3
• oklch

these are different then the palette.css import from OPv2 beta which are dynamic for any hue or chroma amount, they would be static like the hex imports.

hard parts:

• it's alot more colors
• we'll need a really nice testing environment
• we don't have many (or any) good trails to follow for inspiration
• we'll need new docs
• should be able to co-exist with the SDR hex palettes

idea introduced here in #379