Increase clarity of Extract Citations/Fetch PDFs tool

[kilbergr]

This page https://case.law/fetch/ explains its functionality as "Extract citations from a block of text and link to matching cases." During our user study, the subject said she didn't understand what it meant. I realized I too didn't think the explanation reflected the functionality. Catherine agrees.
History is a librarian LIL spoke to brought up wanting to be able to download PDFs of the cases referenced within another case for users. This page was the instantiation of that desire.
We're not sure whether the links to the CAP versions of the cases and the PDFs serve add any value to this offering. It would be easy enough to remove that functionality.
Alternatively, if they do, we could approach by tweaking the guiding text to improve UX.