PROGRESS.md

• Basic diagnostics
• Autocompletion
  • Autocomplete properties
  • Autocomplete values
• Formatting using prettier.
• Docs on hover
• Add CI
• Figure out attribution for stuff from MDN
• Fork tree-sitter-css and adjust to GTK syntax.
  • Jump to definition
  • Better hovering
  • Better auto-completion
  • Documentsymbols
    • Colors defined using @define-color
    • How to represent RuleSets?