demonstrate post-pipeline ERP analysis

[scott-huberty]

It has been suggested to create a new tutorial that demonstrates the process of taking the output of the PyLossless pipeline for a single file, applying the RejectionPolicy to the output, and then doing some ERP related visualization or analysis on that single EEG file.

This was suggested so that users have some example of what they can do with their data after PyLossless, and how they might get there.

I think this is a good idea. For such a tutorial, we can utilize an open access dataset like ERP CORE, or we can use one of MNE-Python's example datasets.