* include_guard requires GLOBAL as family.cmake is included in multiple non child places
* the following recently added check is suprfluous (family_configure_host_example for rp2040 should do this already),
and breaks if pico_pio_usb is not avaialble, so i have removed
# Add pico-pio-usb for rp2040 since user can choose to run on bit-banging host
if(FAMILY STREQUAL "rp2040")
family_add_pico_pio_usb(${PROJECT})
endif()
* added new familt_example_missing_dependency functino to print missing dependency warning, so
pico-examples can override it to be less in your face, and also more contextual to pico-examples
