Clarify `TVTensor` shapes

[mantasu]

📚 The doc issue

TVTensor is documented as being a subclass of torch.Tensor specifically for transforms. Perhaps it could be added that they only constrain the shape of torch.Tensor?

For example, I only use the utility functions of transforms.v2 and, when to_image referred me to Image, I still had to check the source code to confirm it is just a torch.Tensor of shape (C x H x W).

Suggest a potential alternative/fix

No response