Added recipe for Audiobookshelf (swarm)

Has your wife been wishing for a way to consume her DRM-stripped audiobooks on her phone, without having to resort to side-loading apps or media? Fear not, for this new recipe has received 10/10 WAF (wife-acceptance-factor)...

Audiobookshelf is a powerful audiobook / podcast streaming server, whose strength lies in its native app support on Android / iOS (Testflight required).

See the recipe for more!