text: // https://github.com/ghiculescu/jekyll-table-of-contents
  (function($){
      $.fn.toc = function(options) {
        var defaults = {
          noBackToTopLinks: false,
          title: '<i>Jump to...</i>',
          minimumHeaders: 3,
          headers: 'h1, h2, h3, h4, h5, h6',
          listType: 'ol', // values: [ol|ul]
          showEffect: 'show', // values: [show|slideDown|fadeIn|none]
          showSpeed: 'slow', // set to 0 to deactivate effect
          classes: { list: '',
                     item: ''
                   }
        },
        settings = $.extend(defaults, options);
    
        function fixedEncodeURIComponent (str) {
          return encodeURIComponent(str).replace(/[!'()*]/g, function(c) {
            return '%' + c.charCodeAt(0).toString(16);
          });
        }
    
        function createLink (header) {
          var innerText = (header.textContent === undefined) ? header.innerText : header.textContent;
          return "<a href='#" + fixedEncodeURIComponent(header.id) + "'>" + innerText + "</a>";
        }
    
        var headers = $(settings.headers).filter(function() {
          // get all headers with an ID
          var previousSiblingName = $(this).prev().attr( "name" );
          if (!this.id && previousSiblingName) {
            this.id = $(this).attr( "id", previousSiblingName.replace(/\./g, "-") );
          }
          return this.id;
        }), output = $(this);
        if (!headers.length || headers.length < settings.minimumHeaders || !output.length) {
          $(this).hide();
          return;
        }
    
        if (0 === settings.showSpeed) {
          settings.showEffect = 'none';
        }
    
        var render = {
          show: function() { output.hide().html(html).show(settings.showSpeed); },
          slideDown: function() { output.hide().html(html).slideDown(settings.showSpeed); },
          fadeIn: function() { output.hide().html(html).fadeIn(settings.showSpeed); },
          none: function() { output.html(html); }
        };
    
        var get_level = function(ele) { return parseInt(ele.nodeName.replace("H", ""), 10); };
        var highest_level = headers.map(function(_, ele) { return get_level(ele); }).get().sort()[0];
        var return_to_top = '<i class="icon-arrow-up back-to-top"> </i>';
    
        var level = get_level(headers[0]),
          this_level,
          html = settings.title + " <" +settings.listType + " class=\"" + settings.classes.list +"\">";
        headers.on('click', function() {
          if (!settings.noBackToTopLinks) {
            window.location.hash = this.id;
          }
        })
        .addClass('clickable-header')
        .each(function(_, header) {
          this_level = get_level(header);
          if (!settings.noBackToTopLinks && this_level === highest_level) {
            $(header).addClass('top-level-header').after(return_to_top);
          }
          if (this_level === level) // same level as before; same indenting
            html += "<li class=\"" + settings.classes.item + "\">" + createLink(header);
          else if (this_level <= level){ // higher level than before; end parent ol
            for(var i = this_level; i < level; i++) {
              html += "</li></"+settings.listType+">"
            }
            html += "<li class=\"" + settings.classes.item + "\">" + createLink(header);
          }
          else if (this_level > level) { // lower level than before; expand the previous to contain a ol
            for(i = this_level; i > level; i--) {
              html += "<" + settings.listType + " class=\"" + settings.classes.list +"\">" +
                      "<li class=\"" + settings.classes.item + "\">"
            }
            html += createLink(header);
          }
          level = this_level; // update for the next one
        });
        html += "</"+settings.listType+">";
        if (!settings.noBackToTopLinks) {
          $(document).on('click', '.back-to-top', function() {
            $(window).scrollTop(0);
            window.location.hash = '';
          });
        }
    
        render[settings.showEffect]();
      };
  })(jQuery);