Quill editing library from https://quilljs.com/

The version now in use is version 1.3.6.

The Quill operational code currently consist of the following files:
- quill.bubble.css
- quill.core.css
- quill.core.js
- quill.js
- quill.min.js
- quill.min.js.map
- quill.notes.css
- quill.snow.css

The Quill operational code is in minified form and in webpack format.

The Quill operational code was downloaded from a public release of Quill.
https://github.com/quilljs/quill/releases

