Add Move timestamp to messages in game chat

[hs-burke]

Hi there,

It would be immensely helpful to see when a message was sent during a game, by move. E.g.

"I think my position is worse here Move 12"

"Curious to see whether or not that was a blunder Move 25"

Would love to see this implemented, and if anyone has the time, would also love to know how/where this gets implemented in the codebase!

Thanks