Add some type information for events that are sent to the client.

This isn't really used for anything in particular except documentation

src/types/client_data.d.ts

@@ -0,0 +1,26 @@
+interface response {
+	success: boolean;
+	message?: string;
+}
+
+interface HostInformation extends response {
+	// properties depend on `success` being `true`
+	game_code?: string;
+	players?: string[];
+}
+
+// Event is only emitted when the JoinGame event is successful, so there is no
+// success indicator in this response
+interface NewPlayer {
+	player: string;
+}
+
+interface GameJoined extends response {
+	// properties depend on `success` being `true`
+	players: string[];
+}
+
+interface PlayerListResponse extends response {
+	// properties depend on `success` being `true`
+	players: string[]
+}