[Keyboard] Add Encoder map support for rart (#18851)

keyboards/rart/rart75hs/keymaps/via/keymap.c

@@ -53,3 +53,12 @@ const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
   )
 
 };
+
+#if defined(ENCODER_MAP_ENABLE)
+const uint16_t PROGMEM encoder_map[][NUM_ENCODERS][2] = {
+    [0] = { ENCODER_CCW_CW(KC_VOLU, KC_VOLD) },
+    [1] = { ENCODER_CCW_CW(KC_TRNS, KC_TRNS) },
+    [2] = { ENCODER_CCW_CW(KC_TRNS, KC_TRNS) },
+    [3] = { ENCODER_CCW_CW(KC_TRNS, KC_TRNS) }
+};
+#endif

keyboards/rart/rart75hs/keymaps/via/rules.mk

@@ -1,2 +1,3 @@
 VIA_ENABLE = yes
 LTO_ENABLE = yes
+ENCODER_MAP_ENABLE = yes

keyboards/rart/rart75hs/rart75hs.c

@@ -28,4 +28,4 @@ bool encoder_update_kb(uint8_t index, bool clockwise) {
     }
     return true;
 }
-#endif
+#endif