Documentation not up to date
The current documentation https://langchain.readthedocs.io/en/latest/modules/agents/getting_started.html seems to not be up to date with version 0.0.117:

```shell
 UserWarning: You are trying to use a chat model. This way of initializing it is no longer supported. Instead, please use: `from langchain.chat_models import ChatOpenAI`
 ```