FRANKFORT, Ky. – As chain stores, bypasses, and sprawling retail corridors continue to reshape America, many once-beloved downtowns have quietly faded into the background, even though locals still feel deeply attached to them. Across the country, these historic Main Streets and old commercial districts often carry the bones of something special and increasingly hard to find: brick storefronts, railroad-era buildings, faded signs, old theaters, c…