undo, axis editing

include/twn_audio.h

@@ -8,6 +8,7 @@
 /* plays audio file at specified channel or at scratch channel if NULL is passed, without ability to refer to it later */
 /* path path must contain valid file extension to infer which file format it is */
 /* supported formats: .ogg, .xm */
+/* mono or stereo only */
 TWN_API void audio_play(const char *audio,
                         const char *channel,    /* optional */
                         bool  repeat,           /* default: false */