使用jQuery/js计数器和Owl Carousel在导航中显示两位数

<ul class="navigation">
  <li><a href="#">Item 1</a></li>
  <li><a href="#">Item 2</a></li>
  <li><a href="#">Item 3</a></li>
  <li><a href="#">Item 4</a></li>
</ul>

$(document).ready(function() {
  $('.navigation li').each(function(index) {
    $(this).prepend('<span class="counter">' + (index + 1) + '</span>');
  });
});

.counter {
  display: inline-block;
  width: 20px;
  height: 20px;
  background-color: #000;
  color: #fff;
  text-align: center;
  border-radius: 50%;
  margin-right: 5px;
}

$(document).ready(function() {
  $('.navigation').owlCarousel({
    items: 4,
    loop: true,
    nav: true,
    dots: false,
    navText: ['<i class="fa fa-chevron-left"></i>', '<i class="fa fa-chevron-right"></i>']
  });
});