docs: update WebGL.md

Author: nattb8

WebGL.md

@@ -1,5 +1,8 @@
 # Implementing Immutable Unity SDK for WebGL
 
+> [!WARNING]  
+> WebGL functionality is not officially supported.
+
 This guide provides focused instructions for implementing the Unity-Immutable-SDK in WebGL projects.
 
 For general information on the SDK, please refer to
@@ -72,4 +75,4 @@ public class InitPassport : MonoBehaviour
 4. Choose a directory for the build output
 Your WebGL application will open in your default web browser once the build is complete.
 
-For a complete working example, refer to the sample application in the SDK repository.
+For a complete working example, refer to the sample application in the SDK repository.