DOCS: fix docstring validation errors for pandas.Series.str
Partially addresses https://github.com/pandas-dev/pandas/issues/59592

Fixes:
````
 -i "pandas.Series.str.wrap RT03,SA01" \ 
 -i "pandas.Series.str.zfill RT03" \ 
````
Thanks @wenchen-cai  hii @wenchen-cai  i am also trying to contribute but facing some issue can you help me please 