fix new phpstan issues

src/Bundle/ChillMainBundle/Search/SearchInterface.php

@@ -71,9 +71,9 @@ interface SearchInterface
      * @param array  $terms   the string to search
      * @param int    $start   the first result (for pagination)
      * @param int    $limit   the number of result (for pagination)
-     * @param string $format  The format for result
+     * @param "html"|"json" $format  The format for result
      *
-     * @return string, an HTML string
+     * @return string|array a string if format is html, an array if format is json
      */
     public function renderResult(array $terms, $start = 0, $limit = 50, array $options = [], $format = 'html');