Document adding scene-unique nodes by prefixing with '%'

tutorials/scripting/scene_unique_nodes.rst

@@ -18,6 +18,8 @@ the node's path is changed.
 Creation and usage
 ------------------
 
+There are two ways to create a scene unique node.
+
 In the Scene tree dock, right-click on a node and select
 **Access as Unique Name** in the context menu.
 
@@ -28,6 +30,9 @@ to its name in the scene tree:
 
 .. image:: img/percent.webp
 
+You can also do this while renaming the node by adding "%" to the beginning of the name.
+Once you confirm, the percent symbol will appear next to its name.
+
 You can now use the node in your script. For example, you can reference it with
 a ``get_node()`` method call by typing the % symbol, followed by the node's
 name: