chore(docs): update client docstring (#159)

Author: stainless-app[bot]

src/asktable/_client.py

@@ -314,7 +314,7 @@ def __init__(
         # part of our public interface in the future.
         _strict_response_validation: bool = False,
     ) -> None:
-        """Construct a new async Asktable client instance.
+        """Construct a new async AsyncAsktable client instance.
 
         This automatically infers the `api_key` argument from the `ASKTABLE_API_KEY` environment variable if it is not provided.
         """