[Bug Fix]: Correct Image Folder Structure for train_vae.py Training Script

[nnh12]

The script train_vae.py failed with a FileNotFoundError while initializing the ImageFolder dataset due to the absence of class folder strucuture. This PR change correctly moves the images to the correct image directory.

nathan:~/new/DALLE-pytorch$ python3 train_vae.py --image_folder ~/new/DALLE-pytorch/images
Traceback (most recent call last):
  File "/home/nathan/new/DALLE-pytorch/train_vae.py", line 113, in <module>
    ds = ImageFolder(
  File "/home/nathan/.local/lib/python3.10/site-packages/torchvision/datasets/folder.py", line 328, in __init__
    super().__init__(
  File "/home/nathan/.local/lib/python3.10/site-packages/torchvision/datasets/folder.py", line 149, in __init__
    classes, class_to_idx = self.find_classes(self.root)
  File "/home/nathan/.local/lib/python3.10/site-packages/torchvision/datasets/folder.py", line 234, in find_classes
    return find_classes(directory)
  File "/home/nathan/.local/lib/python3.10/site-packages/torchvision/datasets/folder.py", line 43, in find_classes
    raise FileNotFoundError(f"Couldn't find any class folder in {directory}.")
FileNotFoundError: Couldn't find any class folder in /home/nathan/new/DALLE-pytorch/images.