docs: request and response for payments route

[Sangamesh26]

Type of Change

• [x] Enhancement

Description

Docs for request and response in the payments routes.

Motivation and Context

Added docs for the request and responses in payments routes

Checklist

• [x] I formatted the code cargo +nightly fmt --all
• [x] I addressed lints thrown by cargo clippy
• [x] I reviewed submitted code