ir_nec examples require nec libraries in parent folder

[lsellens]

I wanted to create a project from the ir_nec pio example.
https://github.com/raspberrypi/pico-examples/tree/master/pio/ir_nec
Only part of the example is available in the drop down which is the ir_loopback, but it doesn't pull in the nec_receive_library or the nec_transmit_library of which both are needed for the ir_loopback example. I manually got it sorted, but since this is a work in progress extension of which I am very excited about I thought I'd make a issue report so it could get fixed.

[will-v-pi]

Thanks for the report - for now, I'll remove this example as there isn't support for examples that use separate libraries, but leave this open for adding support for that in the future