Fixed incorrect number

https://github.com/godotengine/godot-docs/issues/2329#issuecomment-483379310

getting_started/step_by_step/instancing.rst

@@ -104,7 +104,7 @@ Press "Play" and notice that all of the instanced balls are now
 much more bouncy. Because the instanced balls are based on the saved scene,
 changes to that scene will affect all instances.
 
-You can also adjust individual instances. Set the bounce value back to ``0.5``
+You can also adjust individual instances. Set the bounce value back to ``0``
 and then in the ``Main`` scene, select one of the instanced balls. Set its
 ``Bounce`` to ``1`` and press "Play".