Display non-image attachments with Trix/action_text

I've got the barebones functionality of Trix working ok... The editor displays ok and text and images display as expected. But when I drag and drop a PDF (for example) I can see in the editor a small box with the file title and size display, once its saved the only thing its displayed is, again, the file title and size with no link to a download or anything... the generated html looks promising as it includes some sort of json value inside a 'figure' tag but no idea how to display that...