Use subject images or videos to preview recent subjects (#4578)
Use subject images or videos to preview recent subjects (#4578)

* Fix previews of recent subjects
Use the same code as Talk subject previews. Find the first image or video in the subject locations and use that as the subject preview.

* Appease ESLint!

amyrebecca/Panoptes-Front-End,amyrebecca/Panoptes-Front-End,amyrebecca/Panoptes-Front-End,zooniverse/Panoptes-Front-End