[Docs] Remove combo count from array (qmk#20511)

Author: filterpaper

docs/feature_combo.md

@@ -58,7 +58,7 @@ const uint16_t PROGMEM jk_combo[] = {KC_J, KC_K, COMBO_END};
 const uint16_t PROGMEM qw_combo[] = {KC_Q, KC_W, COMBO_END};
 const uint16_t PROGMEM sd_combo[] = {KC_S, KC_D, COMBO_END};
 
-combo_t key_combos[COMBO_COUNT] = {
+combo_t key_combos[] = {
   [AB_ESC] = COMBO(ab_combo, KC_ESC),
   [JK_TAB] = COMBO(jk_combo, KC_TAB),
   [QW_SFT] = COMBO(qw_combo, KC_LSFT),