Have a convo about domains for joplin

### As a content author I want URLs for the author interface to have a logical & intuitive relationship with the resident site so that I can easily understand their relationship & have trust in the system.
**Is your feature request related to a problem? Please describe.**
Eventually, we will have authors/admins outside of ODD interacting with joplin. Setting aside the fact that even the term joplin is a bit inside baseball, http://joplin.herokuapp.com/ is hardly an intuitive or professional URL to instruct people to visit.

**Describe the solution you'd like**
I'm not aware of any potential blockers here, but something like https://alpha.austin.gov/admin or admin.alpha.austin.gov ought to be able to be set up to redirect to joplin.