Add 'pip install' step to top of notebooks

[richieM]

It would be helpful to explicitly add a !pip install langchain openai cell to the top of the LangChain Cookbooks. Otherwise, users have to play whack-a-mole with installing some packages as they work down the notebook.

[lebsral]

and maybe?

%pip install dotenv

[gkamradt]

Agree! This is on the list of house keeping updates I'm going to work on towards the end of the month or early next month. Thanks for the heads up