Description

Creates a new lint that detects when an attribute value is invalid

Motivation and Context

Helps users discover values that may not be usable by a user-agent

How Has This Been Tested?

• w3c
• Unit tests
• Helix

This lint has also uncovered some issues with parsing. That which isn't fixed in this PR will be fixed upstream in lightningcss (parcel-bundler/lightningcss#1106)

Types of changes

Fixes

• Updates path, d, and points parsing to partially parse partially valid paths, as per spec
• Updates bbox to allow omitting commas, despite spec
• Updates startOffset content-type to length-percentage
• Updates glyph-orientation-horizontal and glyph-orientation-vertical to alow unitless angles

Features

• Adds new lint
• Invalid remaining path data included in path type

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.