This bridge generates feeds for a given search term, optionally
adds the picture to the content and allows for additional query
extensions (GET parameters) to be passed to the bridge. That
way custom filter can be applied without the need to reproduce
them in this bridge (they got a lot!)
Etsy provides a good set of feeds as described here:
https://www.etsy.com/help/article/100
(so there is no need to include them here)
References #492
