Remove reference to CanvasLayer in WebXR example, because it can cause rendering issues in AR.

modules/webxr/doc_classes/WebXRInterface.xml

@@ -14,9 +14,9 @@
         var vr_supported = false
 
         func _ready():
-            # We assume this node has a canvas layer with a button on it as a child.
+            # We assume this node has a button as a child.
             # This button is for the user to consent to entering immersive VR mode.
-            $CanvasLayer/Button.connect("pressed", self, "_on_Button_pressed")
+            $Button.connect("pressed", self, "_on_Button_pressed")
 
             webxr_interface = XRServer.find_interface("WebXR")
             if webxr_interface:
@@ -65,6 +65,7 @@
                 return
 
         func _webxr_session_started():
+            $Button.visible = false
             # This tells Godot to start rendering to the headset.
             get_viewport().xr = true
             # This will be the reference space type you ultimately got, out of the
@@ -73,6 +74,7 @@
             print ("Reference space type: " + webxr_interface.reference_space_type)
 
         func _webxr_session_ended():
+            $Button.visible = true
             # If the user exits immersive mode, then we tell Godot to render to the web
             # page again.
             get_viewport().xr = false