[COMMENTS] added some comments for all the scene files

the only thing i could not find was the on key method, the other params are empty(thus no comments)

src/scenes/startup_Scene.h

@@ -9,13 +9,42 @@ namespace scene
 	class Startup_Scene : public scene::Scene
 	{
 	private:
+		//return_value is an enum that is necessary for the scene switching. Whenever this changes, the scene will change to a different scene.
 		scene::Scenes return_value = scene::Scenes::STARTUP;
 
 	public:
 		~Startup_Scene();
+
+		/**
+		 * @brief the method start is the start of the start-up scene where a while loop runs, this runs the scene.
+		 * @param window the main window of the application
+		 * @return Scene value that indicates in which scene the application is
+		 */
 		Scenes start(GLFWwindow* window) override;
+
+		/**
+		 * @brief this method renders the models for the start-up scene
+		 * @param
+		 * @return void
+		 */
 		void render() override;
+
+		/**
+		 * @brief this method updates the models/variables for the start-up scene
+		 * @param window the main window of the application
+		 * @return void
+		 */
 		void update(GLFWwindow* window) override;
+
+		/**
+		 * @brief this method updates the models/variables for the start-up scene
+		 * @param window the main window of the application
+		 * @param key this is the keycode on which key has been pressed
+		 * @param scancode -
+		 * @param action-
+		 * @param mods -
+		 * @return void
+		 */
 		void onKey(GLFWwindow* window, int key, int scancode, int action, int mods) override;
 	};
 }