Add privacy examples to quickstart

[MadelineMurray]

Add examples of send-tx that showcase the various types of private transactions (EEA, privacy groups)

We do have a Besu+Orion send transaction example (EEA compliant).
You can find more documentation here:
https://docs.orchestrate.pegasys.tech/en/stable/Howto/Using-Private-Transactions/
For privacy groups, you can send a transaction by specifying that privacy group id directly.
To perform modification on privacy groups, you should use the chain-registry proxy feature to relay your calls directly. Isn't not yet documented and we should add an example, thanks for the suggestion