Update order_management_api.md

Fixed FQN

Author: todomagichere

docs/commerce/order_management/order_management_api.md

@@ -43,7 +43,7 @@ It follows the same search query pattern as other APIs:
 
 ## Create order
 
-To create an order, use the `OrderService::createOrder` method and provide it with the `Ibexa\Contracts\OrderManagement\Value\OrderCreateStruct` object that contains a list of products, purchased quantities, product, total prices, and tax amounts.
+To create an order, use the `OrderService::createOrder` method and provide it with the `Ibexa\Contracts\OrderManagement\Value\Struct\OrderCreateStruct` object that contains a list of products, purchased quantities, product, total prices, and tax amounts.
 
 ``` php
 [[= include_file('code_samples/api/commerce/src/Command/OrderCommand.php', 101, 113) =]]