Mention versionadded in Series.sort_index() doc-string

Author: sahildua2305

pandas/core/generic.py

@@ -2015,16 +2015,19 @@ def sort_values(self, by, axis=0, ascending=True, inplace=False,
             Sort ascending vs. descending
         inplace : bool, default False
             if True, perform operation in-place
+        sort_remaining : bool, default True
+            if true and sorting by level and index is multilevel, sort by other
+            levels too (in order) after sorting by specified level
+
+            .. versionadded:: 0.19.0
+
         kind : {'quicksort', 'mergesort', 'heapsort'}, default 'quicksort'
              Choice of sorting algorithm. See also ndarray.np.sort for more
              information.  `mergesort` is the only stable algorithm. For
              DataFrames, this option is only applied when sorting on a single
              column or label.
         na_position : {'first', 'last'}, default 'last'
              `first` puts NaNs at the beginning, `last` puts NaNs at the end
-        sort_remaining : bool, default True
-            if true and sorting by level and index is multilevel, sort by other
-            levels too (in order) after sorting by specified level
 
         Returns
         -------