docs: function prepareI18n(output) {
      var state = output.getState();
      var i18n = state.getI18n();
      var searchPaths = listSearchPaths(output);
  
      searchPaths
          .reverse()
          .forEach(function(searchPath) {
              var i18nRoot = path.resolve(searchPath, '_i18n');
  
              if (!fs.existsSync(i18nRoot)) return;
              i18n.load(i18nRoot);
          });
  
      return Promise(output);
  }