raspberry pi 400 keyboard hinged wall mount

# keep raspberry pi 400 keyboard out of the way

Print in place hinged keyboard supports. Flip it in slicer for RHS.

- with PETG I had to apply some heat to base of hinge to "crack" it
- the keyboard is not held super securely in place, A future design could extend to the front of the keyboard. Nothing that a bit of glue gun won't help out with.