mention modin and cuDF

Author: LiamConnors

doc/python/px-arguments.md

@@ -52,7 +52,7 @@ df = px.data.iris()
 df.head()
 ```
 
-By default `px.data` functions return a pandas `DataFrame` object, but you can specify an alternative dataframe type using `return_type`. `pandas`, `polars`, and `pyarrow` are supported return types.
+By default `px.data` functions return a pandas `DataFrame` object, but you can specify an alternative dataframe type using `return_type`. `pandas`, `polars`, `pyarrow`, `modin`, and `cuDF` are supported return types.
 
 ```python
 df = px.data.iris(return_type='polars')