Added websockets in imports in main.py

main.py

@@ -4,6 +4,7 @@ from starlette.middleware.sessions import SessionMiddleware
 from starlette.staticfiles import StaticFiles 
 from starlette.responses import FileResponse, RedirectResponse
 from fastapi.templating import Jinja2Templates
+from starlette.websockets import WebSocket
 from contextlib import asynccontextmanager
 from sqlalchemy.orm import Session