Update official tutorials to include all network types

The main tutorial is focused only on LANs, but really we are interested in all three:
LANs, CPNs and OPNs.

There is a notebook floating around that parameterizes the choice, but instead we should have three dedicated tutorials that explain a bit what the networks are meant to do.

Start by locating the main LAN-focused tutorial and the existing notebook that parameterizes the network choice. Use them to plan three dedicated tutorials for LANs, CPNs, and OPNs, each briefly explaining the network's purpose; the work is done when all three network types have clear official tutorials.

Written by the indexing model from the issue text.