By Mollie Quirk Meghan Markle is set to rival Kate Middleton’s brother in business, as the Duchess of Sussex hopes to rake in the cash by selling products from dog treats and chicken feed. Earlier this month, the Meghan delighted fans with an all-new Instagram account that seemingly revealed her new business venture. Meghan appears to be gearing up to launch American Riviera Orchard, a new lifestyle brand based out of her Montecito mansion. According to reports, Meghan, 42, has lodged papers to trademark the initials of her new enterprise, with the papers filed to the US Patent and Trademark O…