qmk_firmware_custom/keyboards/m10a/m10a.h

#pragma once

#include "quantum.h"

#define LAYOUT( \
      k00, k01, k02, \
      k10, k11, k12, \
      k20, k21, k22, \
      k30, k31, k32  \
) \
{ \
    { k00, k01, k02 }, \
    { k10, k11, k12 }, \
    { k20, k21, k22 }, \
    { k30, k31, k32 } \
}