Add docs/examples for AMY-sequenced MIDI output

[bwhitman]

We can sequence MIDI events in AMY directly now, which is useful. We should show this as an example somewhere.

[gmeader]

I’d like to see an example where MIDI events are recorded into a track from MIDI IN and then the track is played back by AMY out the MIDI out port.
Better yet, record MIDI events into track 2 while midi from track 1 is playing. Then play back both tracks such that they are synchronized.