title: How to set a group for the gallery?
body: <p>we have a set of content Elements that we can turn into a gallery.</p>
  
  <p>I just add them a class ".gallery" , with this setup:</p>
  
  <pre><code>$('.gallery').featherlightGallery({
    previousIcon: '',
    nextIcon: ''
  });
  </code></pre>
  
  <p>We wish to have the gallery group for every Content Element, cause there targeting a special topic - but with the actual setup every image inside a.gallery ist shown in that Gallery, so we can switch between this topics which isn´t what we want.</p>
  
  <p>I dont see any info about grouping a Gallery on the docs, is there any other way? Other lightboxes use a data-rel="group1" or something like this. </p>
  
  <p>Any infos about this would be nice.</p>
  
  <p>Cheers </p>