Add to doc arduino udev rule

[stimpfli]

sudo nano /etc/udev/rules.d/99-arduino.rules
ADD with the right idVendor and idProduct.
SUBSYSTEM=="tty", ATTRS{idVendor}=="2341", ATTRS{idProduct}=="0070", SYMLINK+="arduino_trigger", MODE="0666", TAG+="systemd", ENV{SYSTEMD_WANTS}="arduino-ready.service"

sudo udevadm control --reload-rules
sudo udevadm trigger