Merge pull request matplotlib#2427 from jarondl/add-Axes-api-doc

DOC: Add axes_api to documentation after the refactoring

Author: pelson

doc/api/axes_api.rst

@@ -6,8 +6,7 @@ axes
 :mod:`matplotlib.axes`
 ======================
 
-.. automodule:: matplotlib.axes
+.. autoclass:: matplotlib.axes.Axes
    :members:
    :undoc-members:
-   :show-inheritance: