Fix style violation

src/Mpociot/ApiDoc/Generators/AbstractGenerator.php

@@ -100,9 +100,10 @@ abstract class AbstractGenerator
     }
 
     /**
-     * Format the validation rules as plain array
+     * Format the validation rules as plain array.
      *
      * @param array $rules
+     *
      * @return array
      */
     protected function simplifyRules($rules)