Add FOIA'ed opinions from the Office of Legal Counsel (OLC)

[mlissner]

Inside the Whitehouse, they have a little office called the Office of Legal Counsel that the exec branch can use to ask random legal questions. Some of the decisions that come out of this office are pretty out there, and the opinions are often really hard to get.

Well, it turns out that Knight First Amendment Institute has been working on getting them out and had a big win today:

https://knightcolumbia.org/content/office-of-legal-counsel-ordered-to-release-many-of-its-legal-opinions

Assuming this isn't appealed, we should grab the decisions once they're published and put them into our system.

We already have 134 of these, which we did as an earlier one-off project:

freelawproject/juriscraper#477

And we have a backscraper in the works too:

freelawproject/juriscraper#1006