When --device is omitted or set to 0, the bridge listens to all
broadcasting ANT+ trainers instead of filtering by a specific device.
The actual transmitting device ID is shown in data logs, allowing
users to discover and then filter specific trainers.
Also fix vendorID/productID not being assigned to config struct
which caused ListenForTrainer to receive 0 for both values.
Add comprehensive README.md covering project purpose, CLI usage,
and troubleshooting. Document the udev rule needed to prevent
usbserial from claiming the ANT+ dongle.
Add Tested hardware section listing the ANT USBStick2 and update
setup.md dmesg output accordingly.
Note: the bridge must be run as root to access the USB dongle.
