code: function filterDocument(doc, threshold) {
    var sections = doc.split(re.mdSplit);
    var out = [];
    var i = 0;
  
    for (i = 0; i < sections.length; i++) {
      // 1. Raw input to preserve
      out.push(sections[i]);
  
      // Iterate
      i++;
      if (i >= sections.length) {
        break;
      }
  
      // 2. Header level
      let level = sections[i];
  
      if (level === undefined) {
        level = 1;
      }
  
      // Iterate
      i++;
      if (i >= sections.length) {
        break;
      }
  
      // 3. File name
      out.push(loadFile(sections[i], level, threshold));
    }
  
    return out.join('');
  }
docs: Filter Markdown document for our placeholders
  
  Visibility threshold can be:
  
  0: public only
  1: public and protected
  2: public, protected and private
  
  @param {String} doc Input document
  @param {Number} threshold Visibility threshold
  
  @return {String} Updated document