doc: remove 'Creating redirect:' build output
doc: remove 'Creating redirect:' build output

This is noisy and getting in the way when I try to read the actual
warnings and errors in the output.

Signed-off-by: Martí Bolívar <9d90ac4c7bf6a305f6bfd81a23c7859bc883380e@nordicsemi.no>

Vudentz/zephyr,Vudentz/zephyr,galak/zephyr,finikorg/zephyr,galak/zephyr,galak/zephyr,nashif/zephyr,nashif/zephyr,Vudentz/zephyr,nashif/zephyr,nashif/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,finikorg/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,finikorg/zephyr,nashif/zephyr