Adding document downloading to Legistar_scraper

[krammy19]

Our Legistar_scraper code outputs a dataframe of document metadata, including the download url. We need to build out this script to add arguments to download these files.

It would be best if downloading documents was an optional argument that could be added via the command arguments similar to those already included in the script.

Ideally the document filenames should be downloaded under this format:

({City} {Agency name} {Date}) i.e. "San Jose City Council 03-14-2021"