message: Avoid duplicate Download Folder buttons
diff: @@ -5,10 +5,10 @@ import * as pageDetect from '../libs/page-detect';
  export default () => {
  if (pageDetect.isRepoTree()) {
  const buttonGroup = select(`.file-navigation .BtnGroup.float-right`);
  - if (buttonGroup) {
  + if (buttonGroup && !select.exists('.rgh-download-folder')) {
  buttonGroup.prepend(
  <a
  - class="btn btn-sm BtnGroup-item"
  + class="btn btn-sm BtnGroup-item rgh-download-folder"
  href={`https://download-directory.github.io/?url=${location.href}`}>
  Download
  </a>);
  