Version 2.5.0

JSDoc type updates.

1. Used /** @type {Object.<string, any>}*/(node).newProperty, casting Node to generic object, allowing addition of new properties.
2. Added other minor type improvements across files.
3. Removed @description tag since the first block of text in a JSDoc comment is treated as the description automatically.
4. Updated test files to use favicons to avoid unnecessary warnings in browser console.
5. Moved build functionality from gulpfile to NPM command line script. Running Rollup from command line.
6. Added rollup.config.js file to project.