Better document setup needs when installing Poseidon (specifically with Faucet)

[cglewis]

• what is the name of the switch for mirroring (name defined in the faucet.yaml, not dns, for example)
• the port that Poseidon uses for mirroring needs to be controlled by Faucet, therefore it needs to be an openflow port
• the port that Poseidon uses needs to be configured in faucet.yaml to be output_only: true and no native vlan (a port for mirroring from Faucet's perspective)
• Requirements if Poseidon and Faucet are deployed on the same machine: at least 2 ethernet connections, one for control plane for Faucet and one for mirroring for Poseidon. Additionally another connection of some sort (wifi or wired) for internet connectivity, at least to get things initially setup.
• Pika errors on Poseidon restart are not actually an issue to worry about.
• Document using ./helpers/faucet/run
• Note about what to expect on startup, if no learn event in faucet, or in poseidon what does it most likely mean, etc.

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[github-actions]

This issue was closed because it has been stalled for 5 days with no activity.