Add docs and types for the game.join event

common/src/types/events/game_join.ts

@@ -0,0 +1,13 @@
+import { ServerResponse } from "../ServerResponse";
+import { PlayerData } from "../PlayerData";
+
+/** The data required by the server to be able to join a game */
+export interface IGameJoinRequest {
+	id: string;
+	name: string;
+}
+
+/** The response that the player receives upon succesfully joining a game. */
+export interface IGameJoinResponse extends ServerResponse {
+	players?: PlayerData[];
+}