Merge pull request #41713 from Yetizone/3.2

Mention Viewport.render_target_clear_mode property is intended for 2D usage

doc/classes/Viewport.xml

@@ -267,6 +267,7 @@
 		</member>
 		<member name="render_target_clear_mode" type="int" setter="set_clear_mode" getter="get_clear_mode" enum="Viewport.ClearMode" default="0">
 			The clear mode when viewport used as a render target.
+			[b]Note:[/b] This property is intended for 2D usage.
 		</member>
 		<member name="render_target_update_mode" type="int" setter="set_update_mode" getter="get_update_mode" enum="Viewport.UpdateMode" default="2">
 			The update mode when viewport used as a render target.