It’s unbaaaa-lievable. After a powerful tornado barreled through Enid, Okla., on April 23, the Sloat family was trapped beneath the earth in their storm shelter under tons of debris when they were suddenly rescued — by their two pet goats. “They saved us,” Adam Sloat, 53, told The Post. “No doubt about it.” The terrifying ordeal began when the approaching storm triggered a rare tornado emergency, the National Weather Service’s highest tornado warning. The bad news: a powerful EF-4 tornado —