Fix option name in ORM package's README

Refs cakephp/orm#11

src/ORM/README.md

@@ -32,7 +32,7 @@ ConnectionManager::config('default', [
 	'database' => 'test',
 	'username' => 'root',
 	'password' => 'secret',
-	'cacheMetaData' => false // If set to `true` you need to install the optional "cakephp/cache" package.
+	'cacheMetadata' => false // If set to `true` you need to install the optional "cakephp/cache" package.
 ]);
 ```