Using Matrix as a decentralized backend

This one might be a major architectural change but in order to allow multiple governance forums stay in sync it would be great if they all store conversations in a standardized(and decentralized) way.

Matrix is a decentralized(federated) communications protocol already used extensively in the Polkadot ecosystem(usually via Element) that stores messages in rooms that can be joined by other homeservers that replicate and store messages on their own while keeping eventual consistency.

One way we can leverage the protocol in governance forums(or any forum) is to see each individual proposal/post as a room, rooms can have data attached to them, custom message types are supported, reactions, replies, notifications, be part of a space(a room that list other rooms) and many more options. The system is quite flexible and well suited to power Polkassembly and any other governance forum in the ecosystem while making them interoperable.