Fix CQRS url - returns 404

[royabhijit]

In the saga design pattern, readme.md file references link to CQRS in the related Java Design patterns section. That page looks like has been removed from the referenced article.

CQRS article is moved here. Correct url needs to be updated.

[Dhiraj-birajdar]

Hi, I'm interested in working on this issue. I'll start working on it.