title: How do I link to an open accordion?
body: <p>I found this <a href="https://codepen.io/anon/pen/VbXOEO" rel="nofollow noreferrer">accordion</a> suitable for what I'm doing. 
  Now I'd like to force it open its panel when clicking on blabla.com/ab.html#open but I'm not familiar with JQ                                                      </p>
  
  <pre><code>&lt;div class="col-md-6 col-sm-6"&gt;
  &lt;h3&gt;Accordion collapse with rotating icon&lt;/h3&gt;
  &lt;div class="panel-group wrap" id="accordion" role="tablist" aria-multiselectable="true"&gt;
    &lt;div class="panel"&gt;
      &lt;div class="panel-heading" role="tab" id="headingOne"&gt;
        &lt;h4 class="panel-title"&gt;
      &lt;a role="button" data-toggle="collapse" data-parent="#accordion" href="#collapseOne" aria-expanded="true" aria-controls="collapseOne"&gt;
        Collapsible item #1
      &lt;/a&gt;
    &lt;/h4&gt;
      &lt;/div&gt;
      &lt;div id="collapseOne" class="panel-collapse collapse in" role="tabpanel" aria-labelledby="headingOne"&gt;
        &lt;div class="panel-body"&gt;
          Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch.
        &lt;/div&gt;
      &lt;/div&gt;
    &lt;/div&gt;
    &lt;!-- end of panel --&gt;
  
  
  &lt;/div&gt;
  &lt;!-- end of #accordion --&gt;
  </code></pre>
  
  <p>
    </p>
  
  <p>
  </p>
  
  <pre><code>$(document).ready(function() {
   $('.collapse.in').prev('.panel-heading').addClass('active');
  $('#accordion, #bs-collapse')
  .on('show.bs.collapse', function(a) {
    $(a.target).prev('.panel-heading').addClass('active');
  })
  .on('hide.bs.collapse', function(a) {
    $(a.target).prev('.panel-heading').removeClass('active');
  });
  });
  </code></pre>