newsletter support is a go

I talked about adding an email newsletter a few days ago, and today I upgraded the site's theme which now more-properly supports the "subscribe" and "sign in" flows. Neither requires a password - you just verify your email address by clicking on a link in your email.

If you're signed in, you can view the content of this dummy newsletter. I've got a separate collection page at https://www.bakejam.com/newsletter/ to view the archive.