fix max_size parameter name in examples

Author: FoamyGuy

examples/displayio_layout_gridlayout_simpletest.py

@@ -27,7 +27,7 @@
     height=100,
     grid_size=(2, 2),
     cell_padding=8,
-    max_cells=10,
+    max_size=10,
 )
 _labels = []
 

examples/displayio_layout_simpletest.py

@@ -29,7 +29,7 @@
     height=100,
     grid_size=(2, 2),
     cell_padding=8,
-    max_cells=10,
+    max_size=10,
 )
 _labels = []