DOC: groupby.rst examples broken

[jreback]

the df for the groupby.resample examples are hiding the correct frame that was previously being used by the docs below

http://pandas-docs.github.io/pandas-docs-travis/groupby.html#dispatching-to-instance-methods

[gr8h]

Can i contribute to this?

Should i use dff instead df since dff = pd.DataFrame({'A': np.arange(8), 'B': list('aabbbbcc')}) and we need to groupby A?

[gr8h]

I have renamed resample() df to df_re under New syntax to window and resample operations section. pull request