WIP: play the schedule

[robb-j]

I've somewhat jokingly added the groundwork to play the current schedule as audio, it should probably be behind a feature flag or special query parameter? It's very heavily based off of https://brandnewbox.com/inthestacks/ right now, the effects can be tweaked (although I don't know much about audio for this).

At this point I'd be interested in what algorithm you might think is appropriate to convert a schedule someone is working on into a series of notes to play.

whats changed

• There is a new "Play" / "Stop" button at the top of the schedule editor which toggles playing
• There is a new "audio.js" file which has SchedulePlayer in it which is responsible for taking a schedule (I'm not sure how yet) and playing it on loop until stopped
• I imagine App.vue would call SchedulePlayer#setSchedule when the schedule changes and it would change which notes it will play

I also added a note to the readme about developer setup on newer versions of NPM

[robb-j]

Also it would be cool to treat each track as a track and play multiple notes at the same time, could sound pretty gross though!