Docs: Feedback for Join Change Data Capture Records

Hi, I have some feedback about [this page](https://github.com/hazelcast/hz-docs/edit/main/docs/modules/pipelines/pages/cdc-join.adoc)

This example is unnecessarily confusing because of the domain object designing. 'OrdersOfCustomer' is an odd in an OOD sense. Why not have the Customer object have an association with a collection of orders, or... simple have the Customer object extend 'OrdersOfCustomer' class. This would also facilitate a better explanation about the importance of ordered processing of cdc update of order and customer entity state for the same customer id. Alternatively..., maybe just renaming 'OrdersOfCustomer' to 'ShoppingBasket' would help clarify the concept.