Update "Models info" docs page

[billbrod]

After my presentation at Cold Spring Harbor, the big sticking point for many people is about models. While the "models info" page describes what they need in the abstract, would probably be helpful to include examples (either on that page or elsewhere) that shows examples of how to use plenoptic with our models, models from torchvision, and your own custom models. (and add to that, if we find another model zoo?)