List projects that use mopidy.js

[arthurlutz]

I arrived on this project through a problem I'm having with node-red-contrib-mopidy (cf #42 ) and I realise this might also be used with https://github.com/jaedb/iris which I also use, so thanks again !

It would be nice to have a list of projects that use mopidy.js in the README, also enabling developers to see how it is being used (in my usecase trying to find example code for tracklist.add)

[jodal]

I'd welcome a PR adding such a list. It doesn't have to be complete initially, but should at least check the top five Mopidy web frontends and see if they use Mopidy.js.