DOC: New storage_options for read_csv needs a docstring

[Dr-Irv]

Location of the documentation

https://pandas.pydata.org/docs/dev/reference/api/pandas.read_csv.html

Documentation problem

The new storage_options keyword for read_csv and read_table is not documented in the docstring.

Suggested fix for documentation

Add docstring

@martindurant

NOTE: I noticed this when running validate_docstrings locally for read_csv and it reported this.

What this keyword is used for @Dr-Irv
I could fix the docstring, which would help me understand the contribution process for pandas.

[Dr-Irv]

@kshivi99 If you look at files common.py, feather_format.py, parquet.py, pickle.py, stata.py, in the directory pandas/io, you can just copy the docstring from there.

Just be really careful to do validate_docstrings on the changed file to make sure it will render OK.