Pytorch DataSet for MNIST1D

[psteinb]

Hi,

for a course, I wrote a pytorch compatible Dataset class for MNIST1D. The examples in this repo don't require one as such as most do not rely on a torch.utils.data.DataLoader. I am still wondering, if it may makes sense to provide a Dataset compliant class for easier handling of MNIST1D in pytorch based code.

I am happy to send a PR if need be, but wanted to discuss the matter first.

Best, Peter

[greydanus]

A PR featuring this addition would be much appreciated :)