ASA CX-3 Keyboard Support by Zero

ASA provides a simulator of their great CX-3 flight computer on their website: https://online.prepware.com/cx3e/index.html. However, it does not support keyboard which makes it very hard to use with a keyboard. This fixes that.

See https://tangled.org/@itsze.ro/asa-cx3-keyboard/blob/main/README.md for latest information.