Added window

src/Application.hpp

@@ -0,0 +1,24 @@
+#pragma once
+
+class Window;
+
+class Application
+{
+public:
+	static Application& GetInstance()
+	{
+		static Application app;
+		return app;
+	}
+
+public:
+	void Run();
+
+private:
+	bool valid;
+	Window* window;
+
+private:
+	Application();
+	~Application();
+};