Disable documentation URLs

No need in exposing the documentation URLs. As this service might be
available from wherever, a bit obscurity is OK.

document_dealer/main.py

@@ -3,7 +3,7 @@ import fastapi
 from .document_client import DocumentClient
 from .config import get_config
 
-app = fastapi.FastAPI()
+app = fastapi.FastAPI(docs_url=None, redoc_url=None)
 
 config = get_config()