note about redis store

lib/stores/redis.js

@@ -1,3 +1,8 @@
+/**
+ * Note: You very likely want to use your own Redis-based cache store instead
+ * of this one, especially for connection pooling.  This is primarily an
+ * example implementation.
+ */
 function redis_store(args) {
     args = args || {};
     var self = {};