spectrum analyser assignable to a button?

[jflinchbaugh]

would adding another action to be assignable to the user-defined keys take up too much space?

here egzumer did it: https://github.com/egzumer/uv-k5-firmware-custom/pull/478/files

[jflinchbaugh]

I applied that patch locally to f4hwn to see. it works, and it seems to add 20bytes to the size.

I've gone so long without the button assigned, I've gotten used to fn-5 to launch the spectrum analyzer. is it worth the 20 bytes?