refactor(main): replace '/ping' endpoint with root endpoint

The '/ping' endpoint has been replaced with a root endpoint that returns a simple JSON response. This change enhances the API by providing a more intuitive root endpoint for basic connectivity checks.

The new root endpoint returns a JSON object with a greeting message, simplifying the API structure and improving user experience.

main.py

@@ -30,11 +30,9 @@ class ChatCompletionRequest(BaseModel):
     stream: bool = False
     max_tokens: Optional[int] = 1024
 
-
-
-@app.get("/ping")
-def pong():
-    return "Pong"
+@app.get("/")
+def read_root():
+    return {"Hello": "World!"}
 
 @app.get("/models")
 async def get_models():