and adjust puzzle-radio starter code accordingly
this reduces the chance of people using puzzle-radio with the wrong dongle
app (i.e. loopback); that would lead to them getting response different than
what's indicated in the text
I have also added the app name to the dongle / serial-term output:
``` text
deviceid=75fa82ad7588b3c7 channel=20 TxPower=+8dBm app=loopback.hex
```
- VS: you can open more than one folder in the same VS workspace
- current folder in VS code needs to be set to beginner/apps for "Run" to appear
- rename `lsusb` to `usb-list`
- recommend `usb-list` over `lsusb`
- make `serial-term` behave like `screen`
