Merge pull request #40239 from Calinou/doc-scene-tree-create-timer

Mention `SceneTree.create_timer()` in the Timer class documentation

doc/classes/Timer.xml

@@ -5,6 +5,7 @@
 	</brief_description>
 	<description>
 		Counts down a specified interval and emits a signal on reaching 0. Can be set to repeat or "one-shot" mode.
+		[b]Note:[/b] To create an one-shot timer without instantiating a node, use [method SceneTree.create_timer].
 	</description>
 	<tutorials>
 	</tutorials>