[Theme] Dark Horizon theme

Certificate is OK and nothing abnormal about cpu and ram usage.

@ljf mentioned to add legal details on the portal here Google flags my sites as dangerous (Deceptive site ahead) - #141 by ljf

The thread is very long and the only fix I found is to edit the portal to make it “different” from the standard one.

I asked for a review and it took less than 5 minutes to get the flag removed.