Apply general code formatting to some pages in the tutorial section

tutorials/optimization/using_servers.rst

@@ -91,9 +91,11 @@ This is a simple example of how to create a sprite from code and move it using t
 
     extends Node2D
 
-    # VisualServer expects references to be kept around
+
+    # VisualServer expects references to be kept around.
     var sprite
 
+
     func _ready():
         # Create a canvas item, child of this node.
         var ci_rid = VisualServer.canvas_item_create()
@@ -130,9 +132,11 @@ The 3D APIs are different from the 2D ones, so the instantiation API must be use
 
     extends Spatial
 
-    # VisualServer expects references to be kept around
+
+    # VisualServer expects references to be kept around.
     var mesh
 
+
     func _ready():
         # Create a visual instance (for 3D).
         var instance = VisualServer.instance_create()
@@ -157,14 +161,16 @@ and moves a :ref:`CanvasItem <class_CanvasItem>` when the body moves.
 .. tabs::
  .. code-tab:: gdscript GDScript
 
-    # Physics2DServer expects references to be kept around
+    # Physics2DServer expects references to be kept around.
     var body
     var shape
 
+
     func _body_moved(state, index):
         # Created your own canvas item, use it here.
         VisualServer.canvas_item_set_transform(canvas_item, state.transform)
 
+
     func _ready():
         # Create the body.
         body = Physics2DServer.body_create()