Include file attachments in Discovery emails

Discovery macros and emails do not support attachments today. Before an interview, I will email a PDF interview guide to a user ~15 minutes before the session. This is for the interviewee to have open in our session because it will contain instructions on actions to perform in the product. I cannot do this workflow in Discovery.

Hard to send resources to prepare users for an interview properly. Means I need to take manual actions before an interview.

Add attachments (PDF) to macros and manual emails in Discovery