code: function split(nodes) {
      var section = [];
  
      var sections = _.reduce(nodes, function(sections, el) {
          if(el.type === 'hr') {
              sections.push(section);
              section = [];
          } else {
              section.push(el);
          }
  
          return sections;
      }, [])
       // Add remaining nodes
      .concat([section])
      // Exclude empty sections
      .filter(_.negate(_.isEmpty));
  
      // Copy over links (kramed needs them)
      sections.links = nodes.links || {};
  
      return sections;
  }
docs: Split a page up into sections (lesson, exercises, ...)