add hostname aliases to templates

Author: pfaffman

samples/standalone.yml

@@ -49,6 +49,8 @@ env:
   ## TODO: The domain name this Discourse instance will respond to
   ## Required. Discourse will not work with a bare IP number.
   DISCOURSE_HOSTNAME: 'discourse.example.com'
+  ## Other hostnames that should have a valid https certificate for (will redirect to hostname)
+  ## DISCOURSE_HOSTNAME_ALIASES: domain.com,other.domain.com
 
   ## Uncomment if you want the container to be started with the same
   ## hostname (-h option) as specified above (default "$hostname-$config")