DOC: fix link to offset strings in resample method (#15619)

Author: DaanVanHauwermeiren

pandas/core/generic.py

@@ -4360,6 +4360,8 @@ def resample(self, rule, how=None, axis=0, fill_method=None, closed=None,
 
             .. versionadded:: 0.19.0
 
+        Notes
+        -----
         To learn more about the offset strings, please see `this link
         <http://pandas.pydata.org/pandas-docs/stable/timeseries.html#offset-aliases>`__.