QuillJS seems to have a slow development cycle and the 1.3.7 version has reached a point where it is no longer up to date with current standards:

For that reason we should consider looking into implementing alternatives.

The main goal of this project was to generate an easy to use RichTextEditor with a simple but sufficient API for use-cases like form editing, but considering the relatively easy implementation (though highly inspired), I believe it shouldn't be an unreasonable amount of work to extend to other promising RTE frameworks.