2.0.0 – At-rule validation, ignore options and Sass/Less improvements, ESM support

• Added syntaxExtensions option to specify syntax extensions, i.e. sass or/and less. For now the plugin validates CSS only by default
• Added at-rule validation for name, prelude and descriptors
• Added atrules option to extend or alter at-rule syntax definition dictionary or disable at-rule validation when false is passed as a value for the option
• Added ignoreAtrules option to specify at-rule names which should not be validated
• Used isStandardSyntax*() helpers from stylelint to reduce failures for non-standard syntax (e.g. Less or Sass)
• Added support for Less & Sass namespaces, a value with such constructions are ignored now instead of failure (#39)
• Added a column to mismatch error details
• Renamed ignore option into ignoreProperties to be more clear what is ignoring; ignore option is still work but cause to a deprecation warning
• Fixed ignoreValue option to apply for parse errors either (#43)
• Fixed failure on a declaration with a Less variable reference, i.e. ignore such declarations for now
• Stylelint 14.0 support
• Package
  • Changed supported versions of Node.js to ^12.20.0, ^14.13.0 and >=15.0.0
  • Converted to ES modules. However, CommonJS is supported as well (dual module)
  • Bumped css-tree to 2.0 and latest mdn-data dictionaries