Fix Drupal\Core\Render\ElementEmail documentation

Here is the code block.

 * Example usage:
 * @code
 * $form['email'] = array(
 *   '#type' => 'email',
 *   '#title' => $this->t('Email'),
 *   '#pattern' => '*@example.com',
 * );
 * @end
 *
 * @see \Drupal\Core\Render\Element\Render\Textfield

I propose the following.

1. Covert to short array syntax
2. Replace@end with @endcode
3. Fix broken @see reference

Note that @end tag triggers autoloader which is kind of performance issue. See #2557433: Add internal, event, and property to the list of ignored annotations in the plugin annotation system for details.