Allow configuring ipv6 in helm chart? #195

I'm running docker-mailserver in a dualstack setup with some tweaks. Would integrating this into the helm chart be desirable?

I'm using this snippet to make dovecot listen for both ipv4 and ipv6 addresses

    configMaps:
      dualstack:
        create: true
        path: /etc/dovecot/conf.d/90-dualstack.conf
        data: |
          listen = *,::

and manually tweak the service to have ipFamilyPolicy: RequireDualStack. With this I can see both ipv4 and ipv6 clients in the logs connecting to my server.