Document how a note can be shared

[benesjan]

Here is a list of permutations Mike came up with:

• Alice creating a note for Alice, and she doesn't want to encrypt and broadcast the note.
• Alice creating a note for Alice, and she wants to encrypt and broadcast the note to herself via L1, as a storage backup.
• Alice creating a note for Bob, and she wants to broadcast the note to Bob via L1, but doesn't want to constrain encryption within the circuit (i.e. she passes the ciphertext into the circuit (unchecked) as an arg, or via an oracle).
• Alice creating a note for Bob, and she wants to broadcast the note to Bob via L1, constraining the encryption to be correct.
• Alice creating a note for Bob, and she doesn't want to broadcast anything; she'll share the note data with him via carrier pigeon.
• All of the last 3, but Alice wants to broadcast an encryption to herself, as a backup.

This should be documented

[benesjan]

Already tackled