Fix typo and re-order creation

There was a typo in `super()` and in fixing that I thought it a good idea to re-order this file to be a little more linear: creating objects and adding them to other objects, rather than creating objects, adding them, and then mutating them after they've been added.

Author: danielquinn

examples/layout_grid_example.py

@@ -6,10 +6,8 @@
 
 class GridWindow(Gtk.Window):
     def __init__(self):
-        sper().__init__(title="Grid Example")
 
-        grid = Gtk.Grid()
-        self.add(grid)
+        super().__init__(title="Grid Example")
 
         button1 = Gtk.Button(label="Button 1")
         button2 = Gtk.Button(label="Button 2")
@@ -18,13 +16,16 @@ def __init__(self):
         button5 = Gtk.Button(label="Button 5")
         button6 = Gtk.Button(label="Button 6")
 
+        grid = Gtk.Grid()
         grid.add(button1)
         grid.attach(button2, 1, 0, 2, 1)
         grid.attach_next_to(button3, button1, Gtk.PositionType.BOTTOM, 1, 2)
         grid.attach_next_to(button4, button3, Gtk.PositionType.RIGHT, 2, 1)
         grid.attach(button5, 1, 2, 1, 1)
         grid.attach_next_to(button6, button5, Gtk.PositionType.RIGHT, 1, 1)
 
+        self.add(grid)
+
 
 win = GridWindow()
 win.connect("destroy", Gtk.main_quit)