code: function(page) {
              if (this.output.name != 'website') return page;
  
              var lang = this.isLanguageBook()? this.language : '';
              if (lang) lang = lang + '/';
  
              urls.push({
                  url: this.output.toURL(lang + page.path)
              });
  
              return page;
          }
docs: Index page