Not trying to put you down, just want to make sure you are aware of the potential naming conflict (both things are for authoring content) in case that creates a legal headache for you one day.
Yes - I only found out about it after I had my app out there with a feather logo and everything.
However I don't think it will cause big issues, as quilljs is a JS library, while Quill (the app) is targeted directly at Ghost's users who will largely (presumably) be journalists. The slight name confusion within dev circles is something we'll just have to live with.
Not trying to put you down, just want to make sure you are aware of the potential naming conflict (both things are for authoring content) in case that creates a legal headache for you one day.