docs: function fileToOutput(output, filePath) {
      var book = output.getBook();
      var readme = book.getReadme();
      var fileReadme = readme.getFile();
  
      if (
          path.basename(filePath, path.extname(filePath)) == 'README' ||
          (fileReadme.exists() && filePath == fileReadme.getPath())
      ) {
          filePath = path.join(path.dirname(filePath), 'index' + OUTPUT_EXTENSION);
      } else {
          filePath = PathUtils.setExtension(filePath, OUTPUT_EXTENSION);
      }
  
      return LocationUtils.normalize(filePath);
  }