title: Document QueryDSL endpoint with Swagger
body: <p>I'm using Spring Boot Data, QueryDSL and Swagger.
  I've define endpoint like this:</p>
  
  <pre><code>@GetMapping
  public ResponseEntity&lt;?&gt; listOfThings(
          @PageableDefault(size = 20, sort = "uID", direction = Sort.Direction.DESC) final Pageable pageable,
          @QuerydslPredicate(root = Thing.class) final Predicate predicate)
  </code></pre>
  
  <p>However Swagger define only variables: page, size, sort - it doesn't seem to parse Entity to show all fields as filterable.</p>
  
  <p>I have repository like this:</p>
  
  <pre><code>@Repository
  public interface ThingRepository
          extends JpaSpecificationExecutor&lt;Thing&gt;, CrudRepository&lt;Thing, String&gt;, PagingAndSortingRepository&lt;Thing, String&gt;,
          QuerydslPredicateExecutor&lt;Thing&gt;, QuerydslBinderCustomizer&lt;QThing&gt;
  {
      @Override
      default void customize(final QuerydslBindings bindings, final QThing thing)
      {
          bindings.bind(thing.status).first((status, value) -&gt; status.eq(value));
          bindings.bind(thing.recipient).first(StringExpression::containsIgnoreCase);
          bindings.bind(String.class).first((StringPath path, String value) -&gt; path.containsIgnoreCase(value));
      }
  </code></pre>
  
  <p>} </p>
  
  <p>I expect Swagger to display all String fields as filters, especially status &amp; recipient which are strictly defined. </p>