Ability to debounce changes

Thanks to @kdaniel21 and @st3h3n it is now possible to debounce changes. This is a good performance optimization when you have larger documents (>=2mb). Large documents are easy to create when working with the default image handler in quilljs,because it is using base64 image strings,

Checkout the readme for more details how to use the new feature.

USE v13.3.1

some stupid package maintainer released the src files instead of the final build... *facepalm *shame