Identify skyInit and rename game_135c70.c to sky.c

src/include/game/sky.h

@@ -0,0 +1,11 @@
+#ifndef _IN_GAME_SKY_H
+#define _IN_GAME_SKY_H
+#include <ultra64.h>
+#include "types.h"
+
+u32 func0f135c70(void);
+u32 func0f135f08(void);
+void skyInit(void);
+u32 func0f13687c(void);
+
+#endif