Client Signing Tutorial Needs a Testnet

As a developer learning about client signing, I would like to be able to try out the 03_client_signing examples on a testnet, so I can see it all working.

In order to fully demonstrate 03_client_signing, we need to either a) maintain an ongoing testnet, b) update the tutorial with steps on deploying a testnet, or c) update the tutorial to demonstrate on the mainnet.

Might be good to go with option b because running a small toy testnet only takes 2 minutes to deploy, if you have docker.

AC

• Decide on the best solution.
• Implement this solution so that this tutorial is fully functional.
• See if there are any other tutorials that need this change (e.g., anything using https://testnet.hive.blog as a placeholder).