Updated for AirPodsPro2

[blackbunt]

Hello delphiki, i've added some features for myself and want to offer them to you.
Thinks I've added/edited:

• added Airpods2Pro to 'models' in main.py
• copied main.py into get_model.py and modified it, that it displays the character needed to identify new unknown Airpods models
• added time_ns.py because it was missing for me
• added arch package build PKGBUILD to install it as a service

If you have any suggestions for changes and/or improvements, please let me know, because i am not a professional coder and am more of a tinkerer.

Greetings!