No main.py file for training VQ-VAE model

[Aritra93]

As mentioned in the paper, VQ-VAE needs to be trained before the diffusion model can be trained. The instructions say that to train VQ-VAE, the main.py file has to be run. @ThomasMrY, can you please look into the issue? It seems like the main.py file is not uploaded by mistake

[chencyan21]

It seems that main_val.py can work.

change the commend by:

python main_val.py --base configs/autoencoder/{dataset}_vq_4_16.yaml -t --gpus 0,