问我们如何使用Fontawesome类来创建带有图标的手风琴，而不是使用Fontawesome？

EN

var coll = document.getElementsByClassName("accordion-toggle");
for (var i = 0; i < coll.length; i++) {
  coll[i].addEventListener("click", function(evnt) {
  	
    const currClassList = evnt.target.classList;
    if (currClassList.contains('collapsed')) {
        evnt.target.classList.remove("collapsed");
        evnt.target.querySelector('.fa').classList.remove("fa-minus");
        evnt.target.querySelector('.fa').classList.add("fa-plus");
        var content = evnt.target.nextElementSibling;
        content.style.maxHeight = null;
    } else {
      for (var j = 0; j < coll.length; j++) {
           coll[j].classList.remove("collapsed")
           coll[j].nextElementSibling.style.maxHeight = null;
      }
      this.classList.toggle("collapsed");
              evnt.target.querySelector('.fa').classList.remove("fa-plus");
        evnt.target.querySelector('.fa').classList.add("fa-minus");
      var content = this.nextElementSibling;
      if (content.style.maxHeight){
        content.style.maxHeight = null;
      } else {
        content.style.maxHeight = content.scrollHeight + "px";
      }
    }
  });
}

.accordion-toggle {
  background-color: #777;
  color: white;
  cursor: pointer;
  padding: 18px;
  width: calc(100% - 18px);
  border: none;
  text-align: left;
  outline: none;
  font-size: 15px;
}

.collapsed, .accordion-toggle:hover {
  background-color: #555;
}


.collapse {
  padding: 0 18px;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.2s ease-out;
  background-color: #f1f1f1;
}

.container {
  max-width:100%;
}

<link href="https://stackpath.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css" rel="stylesheet"/>
<div class="container">


<h2 class="accordion-toggle">Open Collapsible<i class="fa fa-plus pull-right"></i></h2>
<div id="anyId" class="collapse">
  <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>

<h2 class="accordion-toggle">Open Section 1<i class="fa fa-plus pull-right"></i></h2>
<div class="collapse">
  <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>

</div>