boards/nucleo-g070rb: add short board info and flashing commands
boards/nucleo-g070rb: add short board info and flashing commands

ant9000/RIOT,jasonatran/RIOT,miri64/RIOT,kYc0o/RIOT,ant9000/RIOT,kaspar030/RIOT,RIOT-OS/RIOT,kYc0o/RIOT,kYc0o/RIOT,kYc0o/RIOT,jasonatran/RIOT,kYc0o/RIOT,kaspar030/RIOT,RIOT-OS/RIOT,kaspar030/RIOT,miri64/RIOT,miri64/RIOT,jasonatran/RIOT,jasonatran/RIOT,ant9000/RIOT,RIOT-OS/RIOT,RIOT-OS/RIOT,kaspar030/RIOT,RIOT-OS/RIOT,miri64/RIOT,ant9000/RIOT,miri64/RIOT,kaspar030/RIOT,jasonatran/RIOT,ant9000/RIOT