Documentation, header guards

include/s/s_StateInterfaces.hpp

@@ -1,4 +1,5 @@
-#pragma once
+#ifndef S_STATEINTERFACES_H
+#define S_STATEINTERFACES_H
 
 // Note: Ported from https://github.com/NSMBW-Community/NSMBW-Decomp/tree/master/include/dol/sLib
 // See include/s/README.txt for changes made
@@ -74,3 +75,5 @@ public:
 };
 
 /// @}
+
+#endif