Document Conversion Library Tries to Provide a Preview for Unsupported File Types which is confusing

Summary

Document Conversion Library tries to convert and preview unsupported file types. This results in unsupported files to display an error when we click on the attachment link in the Confluence page.

Steps to reproduce

1. Attach a *.zip file to a page
2. Provide a link the attachment
3. Clicking the link will result into an error

   We can't preview this file.
   You'll have to download the file to view it.

4. Checking the Network requests, an error is found on the :path:/wiki/rest/documentConversion/0.1/conversion/convert/...

   415 Unsupported Media Type

**Note: This includes other unsupported file types (i.e .har, .exe)

Workaround

• There is a macro that (provided by Scott Selberg below) that provides a direct download link. This can be downloaded from https://bitbucket.org/selberg/download-attachment/overview