fix: type interred error for express router (#23)

templates/types/streaming/express/src/routes/chat.route.ts

-import express from "express";
+import express, { Router } from "express";
 import { chatRequest } from "../controllers/chat-request.controller";
 import { chat } from "../controllers/chat.controller";
 
-const llmRouter = express.Router();
+const llmRouter: Router = express.Router();
 
 llmRouter.route("/").post(chat);
 llmRouter.route("/request").post(chatRequest);