Sync tile placements for all players

board-network/src/protocol.rs

@@ -20,6 +20,8 @@ pub enum ClientMessage {
     ///
     /// The server will validate the move and answer with a TilePlaced if the message is valid.
     TileUse(Position2dRef, usize),
+    /// Try to place an equal sign on the board.
+    TilePlaceEqual(Position2dRef),
     /// Try to remove a tile from the board to add it to the hand.
     TileTake(Position2dRef),
     /// Get the server to validate the current player moves.