Add releases in a repo

[max-ostapenko]

Mark every new content release (e.g. version 2020:JP) to be able to subscribe for releases.
Currently there is no way to learn that new localization of Almanac was released.

Hopefully can be implemented as Action.

[rviscomi]

@max-ostapenko could you elaborate on the benefits of releases?

What workflow changes do we need to adopt in order to accommodate them?

[tunetheweb]

Starting to think we should do this after all.

With this action we can update releases on each merge (though ignoring time stamp updates and ebook updates). That would be useful to see what to test.

Then as part of release script being discussed in #1230 we can zip up the generated content and add as a release artifact, so we have a history of generated content.

Would then allow us to see a history of changes, when they were released, and also remind the person releasing what to check for just prior to release.

[tunetheweb]

Closing as have started doing this: https://github.com/HTTPArchive/almanac.httparchive.org/releases/