Update XML documentation for GameWindow(DX)

MonoGame.Framework/GameWindow.cs

@@ -270,6 +270,12 @@ internal void OnFileDrop(FileDropEventArgs e)
 		protected abstract void SetTitle (string title);
 
 #if DIRECTX && WINDOWS
+        /// <summary>
+        /// Create a <see cref="GameWindow"/> based on the given <see cref="Game"/> and a fixed starting size.
+        /// </summary>
+        /// <param name="game">The <see cref="Game"/> to create the <see cref="GameWindow"/> for.</param>
+        /// <param name="width">Initial pixel width to set for the <see cref="GameWindow"/>.</param>
+        /// <param name="height">Initial pixel height to set for the <see cref="GameWindow"/>.</param>
         public static GameWindow Create(Game game, int width, int height)
         {
             var window = new MonoGame.Framework.WinFormsGameWindow((MonoGame.Framework.WinFormsGamePlatform)game.Platform);