[DOC] Find a good way to document instantiated types

[cjnolet]

Our type specialization architecture is convenient and powerful, but it's going to hard to manage as we continue to grow. We should find a good way to keep track of, and document, instantiated functions, classes, and types so that we can better manage them. I think this documentation should also be user-facing so users will know what types they can use to automatically benefit from the shared libs.

[ahendriksen]

This is addressed by #1416 and #1437