Input source Bluetooth/AUX in SoundTouch

I would like to be able to switch to aux or bluetooth input on my Bose SoundTouch speaker. It’s possible using libsoundtouch which is used by the Home Assistant component and would make a rather small change.

I’m rather new to Home Assistant, but willing to try to add this feature myself. Haven’t really read up on the developer documentation yet though. Anything I really need to know before getting started with adding this to the component and creating a pull request?