Is there a way to generate custom fields from an external source, or from a static file?
Ideally, I'd like to be able to create a field interface where my users could select from a list of content items from another CMS source. Ideally, I'd like to be able to hit an endpoint from this external source and then loop it into a custom field in Prismic, such as a dropdown.
I could also upload a TXT/JSON file with this information to generate the field data.