* Expand the "description" field.
* Update "repository" to the modern format, per complaints from the npm CLI.
* Remove "homepage" and "bugs", as they can be inferred from "repository".
* Remove "maintainers", as that is set by npm automatically.
* Remove "contributors", as it was outdated and that data is better tracked on GitHub anyway.
* Remove "directories", since an entry for the "lib" directory does nothing.
* Remove the .npmignore file, since it's redundant with the package.json "files" field.

See jsdom/jsdom@1cd029e

Replaces individual exports assignments with local function declarations and a single module.exports object at the end of the file. This improves code clarity and maintainability by consolidating all exports in one place.

Added detailed JSDoc comments to all major functions in lib/parsers.js to improve code readability and provide better context for parameters and return values. This enhances maintainability and developer experience by clarifying function purposes and usage.

Replaces arrays for global CSS keywords and system colors with Set objects for improved lookup performance. Updates all relevant checks from .includes() to .has().

Introduces an AST_TYPES constant object to centralize AST node type strings and replaces hardcoded type string comparisons throughout the file with references to AST_TYPES. This improves maintainability and reduces the risk of typos or inconsistencies in type checks.

Simplified the extraction of itemValue by replacing regex-based string replacement with a more direct slice operation. This improves readability and maintains the same functionality.

Introduces a shared parseNumericValue helper to unify and simplify parsing of numbers, lengths, percentages, and angles. This reduces code duplication and improves maintainability across parseNumber, parseLength, parsePercentage, parseLengthPercentage, and parseAngle.

Replaces hardcoded 'calc' string with the variable 'name' when assigning the 'name' property in parsedValues. This improves code maintainability and consistency for function parsing.

Introduce a mechanism to auto-generate CSS property definitions in propertyDefinitions.js, and refactor the codebase to use these generated definitions. This will be used eventually in jsdom to replace propertiesWithResolvedValueImplemented in jsdom's lib/jsdom/living/helpers/style-rules.js, allowing jsdom to delegate property metadata management entirely to cssstyle.

Refactor normalize.js into smaller functions with clearer roles.

Replace string literals with constants where possible.

This work is mostly preparatory, but it does fix web-platform-tests/to-upstream/css/cssom/style-border-shorthand-var.html.

Follow-up work will implement the complex logic for expanding shorthands into longhands.

Each property module now exports its property name as `module.exports.property`. This change enables more consistent and DRY usage of property names throughout the codebase, especially for shorthand and initial value maps, reducing hardcoded strings and potential typos.

Simplifies and unifies the logic for determining the priority argument in property setters across background, border, flex, font, margin, and padding property modules. The new approach uses a single conditional to check shorthand and property priorities, improving code clarity and maintainability.

getPropertyDescriptor() is used for the generic getters and setters that do not have implementations in properties/*.js. Change from just parsing CSS and setting it as-is, to handle properties more correctly by using the AST types.

Should help with jsdom/jsdom#3985.