DOC add example of Series.index #51842 (#52780)

Update series.py

DOC add example of Series.index #51842 . A newline between the text and the code is missing.

Author: ggold7046

pandas/core/series.py

@@ -5522,6 +5522,7 @@ def to_period(self, freq: str | None = None, copy: bool | None = None) -> Series
         Index(['Kolkata', 'Chicago', 'Toronto', 'Lisbon'], dtype='object')
 
         To change the index labels of an existing Series:
+
         >>> city_series.index = ['KOL', 'CHI', 'TOR', 'LIS']
         >>> city_series.index
         Index(['KOL', 'CHI', 'TOR', 'LIS'], dtype='object')