boards: nucleo-f070rb: Cleanup documentation
boards: nucleo-f070rb: Cleanup documentation

Signed-off-by: Francois Berder <880c5b95aa239388d35adb184ba52ce6e74e78eb@users.noreply.github.com>

ant9000/RIOT,jasonatran/RIOT,authmillenon/RIOT,yogo1212/RIOT,smlng/RIOT,OTAkeys/RIOT,basilfx/RIOT,jasonatran/RIOT,kaspar030/RIOT,jasonatran/RIOT,miri64/RIOT,yogo1212/RIOT,smlng/RIOT,basilfx/RIOT,OlegHahm/RIOT,smlng/RIOT,OlegHahm/RIOT,RIOT-OS/RIOT,kYc0o/RIOT,ant9000/RIOT,RIOT-OS/RIOT,kaspar030/RIOT,kaspar030/RIOT,authmillenon/RIOT,RIOT-OS/RIOT,jasonatran/RIOT,kaspar030/RIOT,miri64/RIOT,basilfx/RIOT,OTAkeys/RIOT,kYc0o/RIOT,miri64/RIOT,ant9000/RIOT,yogo1212/RIOT,authmillenon/RIOT,OlegHahm/RIOT,OlegHahm/RIOT,smlng/RIOT,ant9000/RIOT,jasonatran/RIOT,ant9000/RIOT,kYc0o/RIOT,basilfx/RIOT,authmillenon/RIOT,miri64/RIOT,authmillenon/RIOT,yogo1212/RIOT,authmillenon/RIOT,yogo1212/RIOT,RIOT-OS/RIOT,miri64/RIOT,kYc0o/RIOT,basilfx/RIOT,smlng/RIOT,OTAkeys/RIOT,OTAkeys/RIOT,OlegHahm/RIOT,OTAkeys/RIOT,yogo1212/RIOT,RIOT-OS/RIOT,kYc0o/RIOT,kaspar030/RIOT