Ditch Brooklyn, millennials. The real place to be is Des Moines, a city with a blossoming culture scene, thriving start-ups, and urban beauty.(VIDEO-AT-LINK) DES MOINES, Iowa—This is too nice a place to spawn a war cry. But if the city had one, it would be the sentiment heard across a downtown populated by baristas, tech start-up founders, musicians, and nonprofit professionals alike: "It's Des Moines against the world." Young people here know what you think of this city. It doesn't need repeating. But ambitious minds are in the process of building a new Des Moines, a tech hub in Silicon...