fix: typo in entity manager configuration example

Author: lauris

README.md

@@ -149,7 +149,7 @@ $app->register(new DoctrineOrmServiceProvider, array(
             // (requires registering a PSR-0 Resource Locator
             // Service Provider)
             array(
-                "type" => "annotations",
+                "type" => "annotation",
                 "namespace" => "Baz\Entities",
                 "resources_namespace" => "Baz\Entities",
             ),