Update axes_grid.py

Author: davidgilbertson

tutorials/toolkits/axes_grid.py

@@ -77,7 +77,7 @@
 side ("left", "right", "top", "bottom") of the original axes.
 
 colorbar whose height (or width) is in sync with the main axes
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+--------------------------------------------------------------
 
 .. figure:: ../../gallery/axes_grid1/images/sphx_glr_simple_colorbar_001.png
    :target: ../../gallery/axes_grid1/simple_colorbar.html