HTML or Markdown in Email Card?

Hello!

This is a fairly simple question, but I haven’t been able to find any answers for it. I’m sending out a weekly email newsletter to members. When I use the email card, is there a way I can add some HTML or use Markdown in the card?

I want to add a divider between the stuff in the email card and the content of the post.

NOTE: I’m using Ghost 3.30.1 in a droplet on DigitalOcean.

Many thanks!!!