Master bug list for first release

[kevinjwalters]

• was_pressed() might be returning True twice for a single press - that happened in YT demo video.
• remove BUG_WORKAROUND in music.py when PWMOut can fail to act on changes to duty_cycle on nRF52840 board adafruit/circuitpython#3387 is fixed

Performance

• not good for updates to the pwm output for write_analog

Memory

• perhaps only 55k left when microbit and music are loaded - keep an eye on this particularly with the compass calibration