Added optional typing

app.py

@@ -1,4 +1,5 @@
 from smolagents import launch_gradio_demo
+from typing import Optional
 from tool import TranslateTool
 
 tool = TranslateTool()

tool.py

@@ -1,6 +1,7 @@
 import asyncio
 from smolagents import Tool
 from googletrans import Translator
+from typing import Optional
 
 
 class TranslateTool(Tool):