docs: function FileSystemLoader(dir, options) {
      this.dir = dir.replace(/\/$/, '');
      this.options = options || (options = {});
      this.posts = [];
      this.files = {};
      this.ignore = {};
      var self = this;
      (options.ignore || FileSystemLoader.ignore).forEach(function (file) {
          self.ignore[file] = true;
      });
      process.nextTick(function () {
          self.loadPosts();
      });
  }