DOC: Add ordered categorical

Author: galuhsahid

doc/source/user_guide/io.rst

@@ -4657,9 +4657,10 @@ See the `Full Documentation <https://github.com/wesm/feather>`__.
                       'd': np.arange(4.0, 7.0, dtype='float64'),
                       'e': [True, False, True],
                       'f': pd.Categorical(list('abc')),
-                      'g': pd.date_range('20130101', periods=3),
-                      'h': pd.date_range('20130101', periods=3, tz='US/Eastern'),
-                      'i': pd.date_range('20130101', periods=3, freq='ns')})
+                      'g': pd.Categorical(list('abc'), ordered=True),
+                      'h': pd.date_range('20130101', periods=3),
+                      'i': pd.date_range('20130101', periods=3, tz='US/Eastern'),
+                      'j': pd.date_range('20130101', periods=3, freq='ns')})
 
    df
    df.dtypes