Add an example of 2D grid generation (#12)

examples/visualization/grid_2d.py

@@ -0,0 +1,14 @@
+from abp.fancy import GraphState
+from abp.util import xyz
+import itertools
+
+psi = GraphState()
+grid = itertools.product(range(10), range(10))
+for i, (x, y) in enumerate(grid):
+    psi.add_qubit(i, position=xyz(x, y, 0), vop=0)
+
+for i in range(50):
+    psi.act_cz(i, i+1)
+
+psi.update()
+