Update order of nodes in key_concepts_overview.rst

For consistency, this change reorders the list of nodes to match the order observed in the screenshot.

getting_started/introduction/key_concepts_overview.rst

@@ -40,8 +40,8 @@ nodes.
 
 .. image:: img/key_concepts_character_nodes.webp
 
-It is made of a ``CharacterBody2D`` node named "Player", a ``Sprite2D``, a
-``Camera2D``, and a ``CollisionShape2D``.
+It is made of a ``CharacterBody2D`` node named "Player", a ``Camera2D``, a
+``Sprite2D``, and a ``CollisionShape2D``.
 
 .. note:: The node names end with "2D" because this is a 2D scene. Their 3D
           counterparts have names that end with "3D". Be aware that "Spatial"