Michael Jantz is our hero. The Cleveland bred folk/indie-rocker moved into the District a few years ago after leaving his mark on the Midwest to save us from our end-of-the-week doldrums. Sunday evenings can be somewhat of a downer, but Jantz has found a way to take back the night…as a weekly host and feature artist at Wonderland Ballroom. He draws talent from both inside the District and beyond, and headlines these intimate shows with…