Update missing API documentation on `GET /users/:id/projects`
What does this MR do?
Added missing API documentation on GET /users/:id/projects
Are there points in the code the reviewer needs to double check?
Yes, check if the cross-linking is done well.
Why was this MR needed?
To add API documentation for user projects
Screenshots (if relevant)
What are the relevant issue numbers?
Closes #41478 (closed)