Use consistent highlight format (qmk#19619)

docs/feature_rgb_matrix.md

@@ -1007,7 +1007,7 @@ bool rgb_matrix_indicators_advanced_user(uint8_t led_min, uint8_t led_max) {
 }
 ```
 
-!> RGB indicators on split keyboards will require state information synced to the slave half (e.g. `#define SPLIT_LAYER_STATE_ENABLE`). See [data sync options](feature_split_keyboard.md#data-sync-options) for more details.
+?> RGB indicators on split keyboards will require state information synced to the slave half (e.g. `#define SPLIT_LAYER_STATE_ENABLE`). See [data sync options](feature_split_keyboard.md#data-sync-options) for more details.
 
 #### Indicators without RGB Matrix Effect