title: Is it possible to mark something as deprecated in typescript?
body: <p>I'm writing typescript definitions for a Javascript API with a deprecated method. Here's an extract of the documentation (they say API but it's just about this single method):</p>
  <blockquote>
  <p>This API has no effect. It has been maintained for compatibility
  purpose.</p>
  </blockquote>
  <p>For compatibility purposes, I would also like to document this method in the definitions file. But if possible, I would like to communicate somehow, that it has been deprecated.</p>
  <p>While my current issue is only about deprecation in a definitions file, I would also like to use this feature in other code. So the question is more general: How can I mark something as deprecated in typescript?</p>