Stop changing attachments to links in Govspeak preview
Stop changing attachments to links in Govspeak preview

This makes the Govspeak preview closer in behaviour to actual Govspeak
rendering and has the nice side effect of avoiding a massive nested loop
on documents with many attachments.

alphagov/specialist-publisher,alphagov/specialist-publisher,alphagov/specialist-publisher-rebuild,alphagov/specialist-publisher,alphagov/specialist-publisher-rebuild,alphagov/specialist-publisher-rebuild,alphagov/specialist-publisher-rebuild