ReactQuill does not work with React 19

[KnisterPeter]

The OSS version is not usable in modern setups with react 19. The dependency react-quill is not supported anymore.

[mmastrac]

@KnisterPeter, I've ported isoflow to React 19 over @ https://github.com/mmastrac/isoflow and published it as x-isoflow-react-19 on npm. I believe I've got it working as before.