Update store on track end - turn stop button back to play button when player ends

[flxwu]

now returns back to:

when track has played to its end.

[flxwu]

Done @feross 👍

[feross]

Hmm, I see that you took my review literally haha. It turns out that dispatch is not actually defined in that browser/player.mjs so this doesn't work.

I'll fix it in a followup commit.

[flxwu]

Actually it does work, although I was wondering how it could work despite dispatch being undefined.

So I added a console output in the event case and it got called everytime dispatch got called by the player.on('end) event. IDK why, but it did the proper event dispatch call :)

[feross]

Oh, that's because I attached dispatch to the window for debugging purposes haha. https://github.com/feross/bitmidi.com/blob/master/src/browser/index.mjs#L13