Allow sharing messages.

[RokeJulianLockhart]

Describe the problem

I'm unable to share a link to a message via this platform, although I can using https://develop.element.io/.

Describe the solution you'd like

Implement this feature. An example is https://matrix.to/#/!wTi9pf32W79iGFWCjajY:beeper.local/$Jp8YDo9Igp3vCSG7cV605HyZFqrOnIiWPjem9RYBxJg:twitter.com?via=beeper.local&via=beeper.com:~:text=Does%20http://oku.club%20have%20a%20public%20API.

Alternatives considered

No response

Additional context

The sole documentation I've located is https://github.com/element-hq/element-web/blob/7a3bc83a554347f83d8b53064c0461181c264e41/docs/config.md#customisation--branding:~:text=permalink_prefix:%20An%20optional%20URL%20pointing%20to%20an%20Element%20Web%20deployment.%20For%20example%2C%20https://app.element.io.%20This%20will%20change%20all%20permalinks%20(via%20the%20%22Share%22%20menus)%20to%20point%20at%20the%20Element%20Web%20deployment%20rather%20than%20matrix.to.