Add support to request body documentation in phpdocs

[terrenatech]

There is some use cases in that the auto-generated documentation of POST request body through validation doesn't matches the expected json. One such example is when the body is a list [ {"id": 1, "name": "one"}, {"id: 2, "name": "two"}], and the standard validation generates an array { "*": {"id": 0, "name": "string"}} as expected body.
Documenting through phpdocs would allow the users to ignore the validation results (which, in the above case, totally works), and define a more precise expected request body.