title: How to document choices in api platform?
body: <p>In API-platform, how do I document the choices for a specific property? I have for example a property deliveryTimeWindow:</p>
  
  <pre><code>/**
   * @var string The delivery timewindow of this order.
   *
   * @ORM\Column
   * @Assert\Choice(callback="getTimeWindows")
   * @Assert\NotBlank()
   */
  private $deliveryTimeWindow;
  </code></pre>
  
  <p>But the only thing I see in the front-end is an example "string". </p>
  
  <p>How do I inform to my end-users that only a specific choice is allowed?</p>