Moved code into the code folder.

code/REDALERT/AUDIOMIX.H

@@ -0,0 +1,14 @@
+// AUDIOMIX.H
+//
+
+
+#pragma once
+
+void AudMix_Init(void);
+const char* GetEffectFileName(int index);
+const char* GetThemeMusicFileName(int index);
+void AudMix_PlayMusic(int musicId);
+const char* GetSpeechFileName(int index);
+void AudMix_QueueVideoAudio(const char* audio_buffer, int length, int rate);
+void AudMix_TickMovieAudio(void);
+void AudMix_SetMusicState(bool musicState);