title: What's the annotation for "Produces" in Swagger annotations and OpenAPI v3.0?
body: <p>On OpenAPI v2.0 and Swagger PHP the annotation for Produces was: </p>
  
  <pre><code> /**
   * @SWG\Get(
   *      path="/posts",
   *      operationId="getPosts",
   *      tags={"Authentication"},
   *      produces="application/json"
   *      summary="Returns the posts",
   *      description="Returns the posts",
   *      @SWG\Response(
   *          response=200,
   *          description="Successful operation"
   *      ),
   * )
   */
  </code></pre>
  
  <p>But On OpenAPI v3.0 and Swagger PHP I cannot find on how to annotate the <em>produces</em> on the documentation it states the it is now an attribute of the response <code>@OA\Response</code> but I can not find an example I already try just putting <code>"content" = "application/json"</code> but it doesn't work.</p>