Adds digital clock example for pico_display

[hoganri]

Starts at 12:00 and allows the user to adjust the hours/minutes using the pico_display buttons

[Gadgetoid]

Thank you!

You should keep currentTimeHours and currentTimeMinutes as integers, and use Python's string formatting to display and right-justify them. EG:

>>> "{:02}:{:02}".format(9, 30)
'09:30'

That would save a lot of unnecessary conversion to/from int.

There are also a few linting errors, which our CI will tell you about here - https://github.com/pimoroni/pimoroni-pico/actions/runs/3193502590/jobs/5218789053

There's also a clock example for Badger 2040 which you might want to draw inspiration from - https://github.com/pimoroni/pimoroni-pico/blob/main/micropython/examples/badger2040/clock.py

[hoganri]

Thanks for the feedback. I believe each of these items are addressed in the new commit.