Scraping reading room links

This is a first pass at scraping reading room links from the various FOIA websites in an attempt to build that into the dataset. There's a new script to scrape and update the reading room links, and then the changes themselves. 

Each agency/department might have multiple reading room links (for a variety of reasons). 

This needs more tests. Also, the reading room links script currently updates the list, instead of overwriting it. It should probably overwrite it. 


This PR is assigned to myself as I'm not completely happy with it quite yet.