Add a tutorial/example using the MNIST dataset

[rvberloo]

I think the MNIST dataset would be a nice candidate for a new Tutorial for ML.NET
I would mainly be interested to see how a dateset with hundreds of columns gets modeled, do we need to make a hardcoded class property for each column?

[JRAlexander]

Thanks, @rvberloo! We've added this to the backlog.

[JRAlexander]

cc: @GalOshri, @asthana86

[GalOshri]

Agreed that's a good tutorial to have.

Regarding reading many columns, an example with the new APIs can be found here. An example with the older APIs can be found here.

[JRAlexander]

Hey @rvberloo! There is an MNIST sample here: https://github.com/dotnet/machinelearning-samples/tree/master/samples/csharp/getting-started/MulticlassClassification_MNIST

[JRAlexander]

Closing as I think this is resolved. Please reopen or comment if that is not the case. Thanks!