Mark `OpenXRCompositionLayer` and its children as experimental

modules/openxr/doc_classes/OpenXRCompositionLayer.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8" ?>
-<class name="OpenXRCompositionLayer" inherits="Node3D" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../../doc/class.xsd">
+<class name="OpenXRCompositionLayer" inherits="Node3D" experimental="" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../../doc/class.xsd">
 	<brief_description>
 		The parent class of all OpenXR composition layer nodes.
 	</brief_description>

modules/openxr/doc_classes/OpenXRCompositionLayerCylinder.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8" ?>
-<class name="OpenXRCompositionLayerCylinder" inherits="OpenXRCompositionLayer" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../../doc/class.xsd">
+<class name="OpenXRCompositionLayerCylinder" inherits="OpenXRCompositionLayer" experimental="" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../../doc/class.xsd">
 	<brief_description>
 		An OpenXR composition layer that is rendered as an internal slice of a cylinder.
 	</brief_description>

modules/openxr/doc_classes/OpenXRCompositionLayerEquirect.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8" ?>
-<class name="OpenXRCompositionLayerEquirect" inherits="OpenXRCompositionLayer" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../../doc/class.xsd">
+<class name="OpenXRCompositionLayerEquirect" inherits="OpenXRCompositionLayer" experimental="" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../../doc/class.xsd">
 	<brief_description>
 		An OpenXR composition layer that is rendered as an internal slice of a sphere.
 	</brief_description>

modules/openxr/doc_classes/OpenXRCompositionLayerQuad.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8" ?>
-<class name="OpenXRCompositionLayerQuad" inherits="OpenXRCompositionLayer" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../../doc/class.xsd">
+<class name="OpenXRCompositionLayerQuad" inherits="OpenXRCompositionLayer" experimental="" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../../doc/class.xsd">
 	<brief_description>
 		An OpenXR composition layer that is rendered as a quad.
 	</brief_description>