qmk-firmware/quantum/template/keymaps/default/keymap.c

#include "%KEYBOARD%.h"

const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
[0] = KEYMAP( /* Base */
  KC_A,  KC_1,  KC_H, \
    KC_TAB,  KC_SPC   \
),
};

const uint16_t PROGMEM fn_actions[] = {

};

const macro_t *action_get_macro(keyrecord_t *record, uint8_t id, uint8_t opt)
{
  // MACRODOWN only works in this function
      switch(id) {
        case 0:
          if (record->event.pressed) {
            register_code(KC_RSFT);
          } else {
            unregister_code(KC_RSFT);
          }
        break;
      }
    return MACRO_NONE;
};


void matrix_init_user(void) {

}

void matrix_scan_user(void) {

}

bool process_record_user(uint16_t keycode, keyrecord_t *record) {
  return true;
}

void led_set_user(uint8_t usb_led) {

}