function prepareDeveloperTools() {
  const baseDir = 'examples';
  const devToolsDir = 'developer-tools';
  console.log(`Preparing developer-tools for deployment.`);

  // Create target folder, if it doesn't exist.
  fs.mkdirSync(path.join('gh-pages', baseDir, devToolsDir), {recursive: true});

  // Copy all files from `dist/` subdirectory into the corresponding gh-pages directory
  return gulp
    .src('./examples/developer-tools/dist/*')
    .pipe(gulp.dest('./gh-pages/examples/developer-tools'));
}
Copies the files from the developer-tools dist directory into
the gh-pages directory.

This is treated separately from other examples because it doesn't
get the same page chrome added to it.
@returns {Function | undefined} Gulp task.