Stop animation bug

[MBurtsev]

Hi, Than I added new field in PositionUpdateJob struct https://github.com/stella3d/job-system-cookbook/blob/master/Assets/Scripts/AccelerationParallelFor.cs line36 the сubes stopped moving. My code:

```struct PositionUpdateJob : IJobParallelForTransform
{
    [ReadOnly]
    public NativeArray<Vector3> velocity;  // the velocities from AccelerationJob

    [ReadOnly]
    public Transform[] trans; // here

    public float deltaTime;
    
    public void Execute(int i, TransformAccess transform)
    {
        //trans[i].LookAt(Camera.main.transform.position);

        transform.position += velocity[i] * deltaTime;
    }
}```

[MBurtsev]

I want to change cubes on quads with textures and they always must LookAt camera position. Like this: