updated .gitattributes, configured CMake to properly handle SteamAudio DLL

src/steam_audio.h

@@ -7,20 +7,21 @@
 #include <godot_cpp/godot.hpp>
 #include<godot_cpp/core/class_db.hpp>
 #include <godot_cpp/classes/ref.hpp>
-#include<godot_cpp/variant/utility_functions.hpp>
-#include<phonon.h>
+#include <godot_cpp/variant/utility_functions.hpp>
+#include <phonon.h>
 
 using namespace godot;
 
-class SteamAudio : RefCounted
+class SteamAudio : public RefCounted
 {
-    GDCLASS( SteamAudio,RefCounted );
+    GDCLASS( SteamAudio,RefCounted ) // NOLINT(readability-use-auto)
+
     private:
         IPLContext context = nullptr;
     protected:
         static void _bind_methods();
     public:
         SteamAudio();
-        ~SteamAudio();
+        ~SteamAudio() override;
     bool initialize();
 };