Document subsample table and presubmission hooks

[donaldcampbelljr]

We had an issue where @nleroy917 wanted to use subsamples but it was difficult to figure out how to use a subsample table AND pass the subsamples to a pipeline.

We discussed using presubmission hooks to send this data along to pipeline. This connection is not clear in the documentation.

[nleroy917]

I think this would be a great place to add that information, right in the use a subsample table section

[donaldcampbelljr]

Can I get some clarity on the workflow that was originally being tried that isn't documented currently? Or are the docs now up to date? It's difficult for me to tell based on the above info.