Email notifications for BOFs

Problem/Motivation

Add email notifications so site admins will be notified when a BOF is submitted.

Proposed resolution

Create the template and add it to the submodule's config. Since BoFs don't currently use moderation, something other than Workbench Email may be required. This could be good incentive to move to different solution, as proposed in ✨ Use Easy Email, ECA to send emails instead of Workbench Email Active .