Changed
Looks like media in wysiwyg can't be captioned like images can.
Should the caption be stored in wysiwyg or in the media?
https://drupal.stackexchange.com/questions/305844/how-to-add-captions-to-media-library-items
TODO: Document media caption options.
Modules
View Image Field Caption on Drupal.orgImage Field Caption
View Entity Reference Media on Drupal.orgEntity Reference Media
> Modify/Add a Caption to a Media item and change it OUTSIDE of the Media item and not inside of it.