Rename examples and update some comments.

[ci skip]

examples/key_prefixing.php

@@ -0,0 +1,36 @@
+<?php
+
+/*
+ * This file is part of the Predis package.
+ *
+ * (c) Daniele Alessandri <suppakilla@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+require __DIR__.'/shared.php';
+
+// Predis can prefix keys found in commands arguments before sending commands to
+// Redis, even for complex commands such as SORT, ZUNIONSTORE and ZINTERSTORE.
+// Prefixing keys can be useful to create user-level namespaces for you keyspace
+// thus reducing the need for separate logical databases in certain scenarios.
+
+$client = new Predis\Client($single_server, array('prefix' => 'nrk:'));
+
+$client->mset(array('foo' => 'bar', 'lol' => 'wut'));
+var_export($client->mget('foo', 'lol'));
+/*
+array (
+  0 => 'bar',
+  1 => 'wut',
+)
+*/
+
+var_export($client->keys('*'));
+/*
+array (
+  0 => 'nrk:foo',
+  1 => 'nrk:lol',
+)
+*/