This is a basic implementation on top of the venerable `rss2email`
script, and is intended to be driven by a timer and the
`rss2email-subscribe` service, which manages the subscribed feeds.
This contains the culmination of work done privately for a few months,
and is intended to be a solid basis for other peoples' experimentations
with setting up single-node, home-server setups using Fedora CoreOS.