Update designs/cache_options.md

Co-authored-by: Umanga Chapagain <uchapaga@redhat.com>

Author: alvaroaleman

designs/cache_options.md

@@ -135,7 +135,7 @@ Options{
     &corev1.ConfgMap{}: {
       Namespaces: map[string]*cache.CacheSetting{
         "": {},                                    // No selector for all namespaces...
-        "operator" {LabelSelector: labelSelector}, // except for the operator namespace
+        "operator": {LabelSelector: labelSelector}, // except for the operator namespace
       },
     },
   },