Webtorrent: Meta issue

* Need to install the WebTorrent Tracker - see https://github.com/internetarchive/dweb-transport/issues/22
* Need to fix CORS on download files, so that we can use archive.org/download/xx/yy to get files. This would benefit other apps - see https://github.com/internetarchive/dweb-gateway/issues/33

When both the above are fixed we need to rewrite Torrent files, at ingestion and either on the fly, or via a batch process. See https://github.com/internetarchive/dweb-gateway/issues/34 and/or https://github.com/internetarchive/dweb-transports/issues/5

Start by reviewing the linked issues in dweb-transport (#22), dweb-gateway (#33 and #34), and dweb-transports (#5) to understand the dependencies and current scope. Done requires the tracker, CORS behavior, and torrent rewriting work to be defined and completed across the referenced projects.

Written by the indexing model from the issue text.