title: Make element visible only for md sized devices
body: <p>according to <a href="https://vuetifyjs.com/en/layout/display" rel="noreferrer">https://vuetifyjs.com/en/layout/display</a> 
  you can hide for a specific device size or range going up or down. But how would you show a div only for md sized devices? <code>hidden-lg-and-up hidden-sm-and-down</code> doesn't seem to work. concatenating <code>hidden-{x}-only</code> also does not seem to work.</p>