Add URLs from papers to the Web Archive

Many websites fall into disrepair and go offline even after being published in a conference paper. One way we can ensure that at least the pages describing a project (if not the corpora, etc) produced by the project) remain accessible is to systematically add each URL featuring in a paper in the ACL anthology to the [Internet Archive](https://web.archive.org).

This would be an **enhancement** improving the archival state of our field going forward.

* [ ] develop scripts to accurately parse URLs in ACL papers wherever text or OCR'd text is available
* [ ] find out the best way to add a list of URLs to the Internet Archive (e.g. is there an API?)
* [ ] write a script to add all URLs published at ACL venues to the Internet Archive
* [ ] run the script once a year / advocate for ACL to encourage or require authors to submit sites that they reference to the archive when camera-ready papers are submitted