How do I add camera rotation while moving a player sideways?

After experimenting for a couple of days I still haven't found a decent manner to rotate a player cam horizontally with the A and D keys (assuming classical mapping). I am aiming for something like the first DOOM's movement. How do I achieve this?

 using UnityEngine;
 
 using System.Collections;
 
 public class MoveyCube : MonoBehaviour 
 
         public float maxSpeed = 6f;           
         public float maxAcelleration = 100;    
         Vector3 movement;                  
         public float acelleration = 0f;        
         Rigidbody playerRigidbody;      
         Vector3 rotatevector;
         int rotspeed;
                   
 
 
         void Awake ()
         {
             playerRigidbody = GetComponent <Rigidbody> ();
         }
 
 
         void FixedUpdate ()
         {
             float h = Input.GetAxisRaw ("Horizontal");
             float v = Input.GetAxisRaw ("Vertical");
 
 
             Move (h, v);
 
             if (acelleration < maxSpeed && Input.GetKey (KeyCode.W) || Input.GetKey (KeyCode.S) || Input.GetKey (KeyCode.A) || Input.GetKey (KeyCode.D)) 
             {
                 acelleration += 1;
                 if (acelleration >= maxSpeed)
                 {
                     acelleration = maxAcelleration;
                 }
             } 
             else 
             {
                 acelleration -= 1;
                 if (acelleration <= 0)
                 {
                     acelleration = 0;
                 }
             }
         }
 
         void Move (float h, float v)
         {
             movement.Set (h, 0f, v);
             movement = Camera.main.transform.TransformDirection(movement);
             movement = movement.normalized * acelleration * Time.deltaTime; // Anti diagonal extra speed measure
             
             playerRigidbody.MovePosition (transform.position + movement);
             rotatevector.Set (0, h, 0);
             Camera.main.transform.Rotate(rotatevector * Time.deltaTime);
 
         }
         
     }