Update XML documentation for GraphicsDebugMessage (#13)

MonoGame.Framework/Graphics/GraphicsDebugMessage.cs

@@ -2,18 +2,42 @@
 // This file is subject to the terms and conditions defined in
 // file 'LICENSE.txt', which is part of this source code package.
 
+// NOTE: This is only used in DirectX contexts (see: GraphicsDebug.DirectX)
+//       The other contexts are set to return an instance with an empty message (see: GraphicsDebug.Native and GraphicsDebug.Default)
+//
+//       So for reference as to the messages received, you can find more information at
+//       https://learn.microsoft.com/en-us/windows/win32/api/d3d11sdklayers/ns-d3d11sdklayers-d3d11_message
+
 namespace Microsoft.Xna.Framework.Graphics
 {
+    /// <summary>
+    /// Represents a debug message from the graphics subsystem.
+    /// </summary>
     public class GraphicsDebugMessage
     {
+        /// <summary>
+        /// Gets or Sets the message.
+        /// </summary>
         public string Message { get; set; }
 
+        /// <summary>
+        /// Gets or Sets the debug severity level of the message.
+        /// </summary>
         public string Severity { get; set; }
 
+        /// <summary>
+        /// Gets or Sets the ID of the debug message.
+        /// </summary>
         public int Id { get; set; }
 
+        /// <summary>
+        /// Gets or Sets the string representation of the debug message ID.
+        /// </summary>
         public string IdName { get; set; }
 
+        /// <summary>
+        /// Gets or Sets the category of the debug message.
+        /// </summary>
         public string Category { get; set; }
     }
 }