Editting request documentation

[R0DR160HM]

When creating a new request and using the method set_host, the method definition says it sets the method of the request rather than the host.

Ex:

let req = request.new()
    |> request.set_method(Get) // Set the method of the request
    |> request.set_host("")    // Set the method of the request

[lpil]

Thank you!