Add a model named "openai" and "--model_list" option

[TimelyToga]

This is in response to #390.

Solution

# Specific model 
--model openai --model_list gpt-4-1106-preview
# Multiple models 
--model openai --model_list gpt-4-1106-preview,gpt-3.5-turbo-0125

Currently this openai model alias is only for this behavior, but I think it should be expanded to be the defacto way to use the OpenAI API. The current approach is a bit messy because chatgptapi and gpt-4 are two separate top-level models.

I opted to add a new model to preserve backwards compatibility, but also paves a path for future CLI improvements.

Edge cases

No --model_list with openai:

First model is not valid

We should probably include some automatic checking to make sure all the models you specify are valid, but since we're using cycle(), this failure should be found within the first N paragraphs.

[yihong0618]

nice and clean code, thanks very much. will check tonight (utc+8)

[TimelyToga]

I just noticed there are some issues with unnecessary whitespace changes in README. Let me fix that.

[yihong0618]

very nice solution and did not make any break change,
I think with your solution we had support openai like api like grog or others.

[TimelyToga]

@yihong0618 wow that's cool! Didn't even realize you had that feature. Thanks for the merge.

[rafaelobo]

Can someone upload an example of using with Groq and Llama3? I would be thankful.

[yihong0618]

Can someone upload an example of using with Groq and Llama3? I would be thankful.

OK