Refactored value model names

Implemented CSS variable resolution #62

Improved computation #136

Updated nested implementation #148

Fixed text align behavior

Added implementation of new color functions #131

Migrated to NUKE

Finished initial implementation of rules #102

Merge pull request #108 from AngleSharp/devel

Release 0.16.4

Merge branch 'main' of https://github.com/AngleSharp/AngleSharp.Css