docs(readme): fix list models example

README.md

@@ -125,7 +125,7 @@ fn main() {
     // This example suppose you have set the `MISTRAL_API_KEY` environment variable.
     let client = Client::new(None, None, None, None);
 
-    let result = client.list_models(model, messages, Some(options)).unwrap();
+    let result = client.list_models().unwrap();
     println!("First Model ID: {:?}", result.data[0].id);
     // => "First Model ID: open-mistral-7b"
 }