chore: add client cheat sheet

examples/storage-cheat-sheet.php

@@ -0,0 +1,12 @@
+<?php
+declare(strict_types=1);
+require "vendor/autoload.php";
+
+use Momento\Auth\CredentialProvider;
+use Momento\Config\Configurations\Storage\Laptop;
+use Momento\Storage\PreviewStorageClient;
+
+$storageClient = new PreviewStorageClient(
+    Laptop::latest(),
+    CredentialProvider::fromEnvironmentVariable("MOMENTO_API_KEY")
+);