Extend the installation docs with a recommendation on how to initialize the environment variables

[pavel-kirienko]

Example for SLCAN:

# Common UAVCAN register configuration for testing & debugging.
# Source this file into your sh/bash/zsh session before using Yakut and other UAVCAN tools.
# Other helpful commands:
#   canbusload -tcbr slcan0@1000000 slcan1@1000000
#   candump -decaxta any

export UAVCAN__CAN__IFACE='socketcan:slcan0 socketcan:slcan1'
export UAVCAN__CAN__MTU=8
export UAVCAN__NODE__ID=$(yakut accommodate)

echo "Auto-selected node-ID for this session: $UAVCAN__NODE__ID"

function init_slcan()
{
    # https://gist.github.com/pavel-kirienko/32e395683e8b7f49e71413aebf5e1a89
    sudo setup_slcan -r /dev/serial/by-id/usb-Zubax*Babel*
}