impl basic player state machine (#198)

src/declarations/@xstate/fsm/index.d.ts

@@ -0,0 +1,22 @@
+import * as fsm from '@xstate/fsm';
+
+declare module '@xstate/fsm' {
+  export namespace StateMachine {
+    interface Service<
+      TContext extends object,
+      TEvent extends fsm.EventObject,
+      TState extends fsm.Typestate<TContext> = any
+    > {
+      send: (event: TEvent | TEvent['type']) => void;
+      subscribe: (
+        listener: StateListener<State<TContext, TEvent, TState>>,
+      ) => {
+        unsubscribe: () => void;
+      };
+      start: () => Service<TContext, TEvent, TState>;
+      stop: () => Service<TContext, TEvent, TState>;
+      readonly status: fsm.InterpreterStatus;
+      readonly state: State<TContext, TEvent, TState>;
+    }
+  }
+}