Issue with context being maintained

[moorecj]

We had an issue maintaining context correctly via the NuGet package. After some investigation it seems the chat gpt response side of the conversion was not being passed back in subsequent calles to the api.

You can see an example of how this should work here: https://cobusgreyling.medium.com/when-using-the-chatgpt-api-users-will-have-to-manage-the-context-ba5869238913

I have submitted a pull request that seems to fix the issue. https://github.com/PawanOsman/ChatGPT.Net/pull/36

Thanks for the hard work!