## Summary
Some minor changes to the network_simulator_demo jupyter notebook so that all cells run.
I've updated the notebook to use a **very lightly** modified version of the ARCD UC2 network that it has been using.
_I've added a single route into the router_1 route table so that `network.get_node_by_hostname("router_1").route_table.show()` returns something visible. I didn't want to have this within the 'normal' uc2 network. Don't @ me._
Corrected a path typo in `basic_lan_network_example()` so it correctly loads that network config.
## Test process
I've not broken any existing tests, and the notebook now runs with fully populated cells.
## Checklist
- [X] PR is linked to a **work item**
- [X] **acceptance criteria** of linked ticket are met
- [X] performed **self-review** of the code
- [X] written **tests** for any new functionality added with this PR
- [X] updated the **documentation** if this PR changes or adds functionality
- [X] written/updated **design docs** if this PR implements new functionality
- [X] updated the **change log**
- [X] ran **pre-commit** checks for code style
- [X] attended to any **TO-DOs** left in the code
Related work items: #2560
417c02eaaa
