Update tutorial and include Mithril

[ch1bo]

Why

We need to further simplify the getting started experience to ultimately "Make Hydra trivial to use". Similar to the demo setup on a devnet, we want to make a more realistic deployment of a two party Hydra Head on a public testnet possible within minutes (e.g. 15 minutes on preprod).

We already have a tutorial on our website, but this is now outdated and contains a lot of details, which would be better situated in the "further reading" sections of core concepts.

What (TBD)

Within this story, we want to update and extend the tutorial to the latest hydra-node version, include Mithril for a fast bootstrap of cardano-nodes and update the instructions to not use local nodes, but a networked setup.

• Update tutorial to latest released version
• Move explanatory parts to core concepts and link there instead
• Make it shorter
• Make it about starting nodes on remote machines, u instances and using a public testnet
• Make each hydra-node use a dedicated cardano-node
• Use Mithril to fast bootstrap cardano-nodes in the setup

This website gives a clear definition what a tutorial is, how it is different to how-to-guides and other documentation and helps in formulating tutorials: https://documentation.divio.com/tutorials/

How

• Make sure Hydra works with Mithril, that includes: Upgrade to cardano-node 8 #1007
• Read https://documentation.divio.com/tutorials/
• Move conceptual pages out of the way
• Define "what" the tutorial will do
• Write tutorial steps Revive tutorial #1035
• Validate steps with the whole team
• Review new core-concepts/scalability page
• Review/merge core-concepts/protocol-outline with core-concepts/index (overview) page
• Test consistency of tutorials using a CI workflow where possible
  • e.g. checking mithril endpoints vs. mithril docs