🚀: UI warning when adding account without directory store

[madsmh]

Which feature or improvement would you like to request?

I was so eager to setup Stalwart that I missed the part in the installation docs about adding a directory store, and this is clearly PICNIC, but it is probably a good idea Stalwart would refuse to add an account if there is no directory store set.

Is your feature request related to a problem?

I'm having a problem with...

Code of Conduct

• [x] I agree to follow this project's Code of Conduct