Document the protocol used by Silence
Created by: keverets
Bug description
Though Silence states that it's based on the signal protocol ("A fork of Signal with only SMS/MMS encryption") that's insufficient for other projects to interoperate with Silence.
To that end, documenting the protocol used would allow for other implementations, or for it to be used in slightly different contexts.
The one under consideration (which motivated the submission of this issue) is JMP.chat which provides a gateway between SMS and XMPP. It would be beneficial for a user of that service to be able to have encrypted communication with Silence-using-contacts from their XMPP clients, rather than forcing that communication to be purely plain-text.