Need minor update for command-line utility prmpt example for python library

[glenl26]

For this page, https://platform.openai.com/docs/libraries/python-library.

$ openai api chat_completions.create -m gpt-3.5-turbo -g user "Hello world"

I believe the model name should be updated to “chat.completions.create” instead of “chat_completetions.create”