Update charts in docs to reflect DeviceModel usage

[rly]

I think the original LucidChart ones were a little easier to read in terms of appearance and how the VectorData type was written, but this also works! I realized every image in this tutorial references the Device class in some way.... Maybe would be better to leave for now and make a separate issue to make sure all these diagrams are up to date and use a consistent display format?

Originally posted by @stephprince in https://github.com/NeurodataWithoutBorders/pynwb/pull/2088#discussion_r2136679045