[Observium] Fortinet Support

I wanted to start by saying Observium is so awesome! I wish I would of found it sooner!

So I'm trying to add my Fortinet firewalls to Observium. I see that I can add specific MIBs for Fortigates, but I didn't see the latest D series on the list. I'm not exactly sure how to add the Fortigates. I'm unable to create a DNS entry for the firewall, and I know it's dependent on DNS. I'm very new and not exactly sure how to go about this addon. Can anybody shed some light and point me in the right direction.

Also, I read that if a custom MIB wasn't written for the device that one can donate. How do I go about doing that? I would love to see the latest Fortinets(and older of course) in Observium.

Cheers,