Update README.md to python bindings

Signed-off-by: Andriy Mulyar <andriy.mulyar@gmail.com>

gpt4all-bindings/python/README.md

@@ -41,13 +41,10 @@ pip3 install -e .
 Test it out! In a Python script or console:
 
 ```python
-
 from gpt4all import GPT4All
-
-gptj = GPT4All("ggml-gpt4all-j-v1.3-groovy")
-messages = [{"role": "user", "content": "Name 3 colors"}]
-gptj.chat_completion(messages)
-
+model = GPT4All("orca-mini-3b.ggmlv3.q4_0.bin")
+output = model.generate("The capital of France is ", max_tokens=3)
+print(output)
 ```
 
 ## Troubleshooting a Local Build