Add domain redirection

[tms0]

Hi,

I miss a domain redirection feature, to handle the redirection of www subdomain to non www domain (for example) .

I think it could be done easily by adding a "Redirect to domain" option in the UI, when we add a domain. Then in caddy, it generates a new route with a static_response handler to redirect to the specified domain.

What do you think about it ?