function prepareToDeployExamples(done) {
  const folders = getExampleFolders();
  return gulp.parallel(
    folders.map(function (folder) {
      return function preDeployExample(done) {
        return prepareExample(folder, false, done);
      };
    }),
    prepareDeveloperTools,
  )(done);
}
Prepare examples/demos for deployment to gh-pages.

For each examples, read the demo config, and copy relevant files to the
gh-pages directory.
@param {Function} done Completed callback.
@returns {Function} Gulp task.