Update usage of OpenAI client

[AbhinavMir]

📥 Pull Request

📘 Description
The Jupyter notebook example currently uses an outdated OpenAI Python library example.

🎯 Goal
Update the usage to reference OpenAI's client correctly.

[areibman]

Technically the same but I think adding the api key in the line adds clarity. So LGTM

[AbhinavMir]

@areibman Hm, weird. Current usage was erroring out with OpenAIError: The api_key client option must be set either by passing api_key to the client or by setting the OPENAI_API_KEY environment variable for me. I was running off the same example mentioned in the docs. Thanks nonetheless! Thought I'd send out what worked for me!

[areibman]

Thank you @AbhinavMir!!