imscJS 2.0.0 release candidate 2

Summary of changes since imscJS 1.1.5:

• uses the native browser DOMParser and removes the sax.js dependency (thanks to @littlespex)
• add support for tts:fontVariant
• move to ES6 modules, typescript definitions and linting (thanks to @littlespex)
• move to modern JS packager and remove Grunt build dependency
• removes conflicts between library symbols and ES symbols
• allow multiple style attributes on element
• improve testing and documentation
• improves generation of reference renders using puppeteer
• improves the reference render comparison script
• Remove deprecated ruby elements

Signatures for fromXML(), generateISD(), and renderHTML() remain unchanged.

Deployed at https://www.npmjs.com/package/imsc/v/2.0.0-rc.2

Release planned for 2026-10-18.

Full Changelog: 1.1.5...2.0.0-rc.2