Airport and dip switch on tx

When using the BetaFPV 2.4 Micro TX module with Airport, it's necessary to set the DIP switches in programming mode instead of "normal" mode (in this case, DIP switches 1 and 2 should be on, and the others off).

https://github.com/ExpressLRS/ExpressLRS/issues/2546

I imagine that this issue is hardware-specific, but it might be helpful for beginners like me if there were a reference in the documentation. Something as simple as "If your TX module has DIP switches, make sure to set them appropriately."