refactor: header file for every module

include/engineSoundtrack.h

@@ -0,0 +1,16 @@
+#ifndef ENGINE_SOUNDTRACK_H
+#define ENGINE_SOUNDTRACK_H
+
+#include <raylib.h>
+#include <stdbool.h>
+
+typedef struct {
+  Music music;
+  bool playing;
+  bool paused;
+} Soundtrack;
+
+Soundtrack LoadSoundtrack(const char *musicPath);
+void UpdateSoundtrack(Soundtrack *soundtrack, bool playing);
+
+#endif // ENGINE_SOUNDTRACK_H