Button sound effect (#312)

* Removed magic number for CARD_FOCUS_SFX_PITCH_OFFSET_RANGE

include/audio_utils.h

@@ -42,10 +42,13 @@
 
 /**
  * @brief Play a sound effect, wrapper for mmEffectEx()
+ * See https://maxmod.org/ref/functions/mm_sound_effect.html
+ * and https://maxmod.org/ref/functions/mmEffectEx.html
  *
  * @param id the sound id to play, from maxmod compiled soundbank.h header
  * @param rate the pitch rate, the default value is @ref MM_BASE_PTCH_RATE
+ * @param volume the volume ranging from 0 (silent) to 255 (loudest)
  */
-void play_sfx(mm_word id, mm_word rate);
+void play_sfx(mm_word id, mm_word rate, mm_byte volume);
 
 #endif