Requesting PyTorch demo code

[AruniRC]

Great work making this available open source as well as in both TF and PyTorch, @rpautrat !

I noticed that your demo script (superpoint/match_features_demo.py) is for the TF version. It might be useful to also make a similar simple demo for the PyTorch version of the model, especially since things like image pre-processing can take some trial and error to get right unless there is a demo.

Thank you!