Just two months after the debut of Fish Taco at Wildwood Shopping Center, the burgeoning chain is set to open its third location next week at the former home of City Burger in Chevy Chase. The Fish Taco concept has been a winner for local restaurateur Francis Namin, who also created City Burger as well as the Don Pollo chicken chain and the much-missed Red Tomato Café in downtown Bethesda. Namin’s upscale Bethesda restaurant, Food Wine & Co., closed its doors a few weeks ago after its building was marked for redevelopment.