Prevent llms/mlx_lm from serving the local directory as a webserver (#498)

* Don't serve local directory

BaseHTTPRequestHandler serves the current directory by default. Definitely not intended behaviour. Remove the "do_HEAD" and "do_GET" methods.

* Fix typo in method name

I assume hanlde_stream was intended to be called handle_stream

* Fix outdated typehint

load_model returns nn.Module, however fetch_from_hub was not updated to reflect the change

* Add some more type hints

* Add warnings for using in prod

Add a warning to README and runtime, discouraging use in production. The warning is the same as on the python docs for HTTPServer https://docs.python.org/3/library/http.server.html

* format

* nits

---------

Co-authored-by: Awni Hannun <awni@apple.com>

llms/mlx_lm/SERVER.md

@@ -4,6 +4,10 @@ You use `mlx-lm` to make an HTTP API for generating text with any supported
 model. The HTTP API is intended to be similar to the [OpenAI chat
 API](https://platform.openai.com/docs/api-reference).
 
+> [!NOTE]  
+> The MLX LM server is not recommended for production as it only implements
+> basic security checks.
+
 Start the server with: 
 
 ```shell
@@ -61,5 +65,9 @@ curl localhost:8080/v1/chat/completions \
 
 - `top_p`: (Optional) A float specifying the nucleus sampling parameter.
   Defaults to `1.0`.
-- `repetition_penalty`: (Optional) Applies a penalty to repeated tokens. Defaults to `1.0`.
-- `repetition_context_size`: (Optional) The size of the context window for applying repetition penalty. Defaults to `20`.
+
+- `repetition_penalty`: (Optional) Applies a penalty to repeated tokens.
+  Defaults to `1.0`.
+
+- `repetition_context_size`: (Optional) The size of the context window for
+  applying repetition penalty. Defaults to `20`.