refactor(main_no_modal.py): add check for file_path ending with "/" before writing to file

[jonnyhoff]

style(main_no_modal.py): change openai_model from gpt-4 to gpt-3.5-turbo refactor(main_no_modal.py): add check for file_path ending with "/" before writing to file

[swyxio]

1. lets make it respect a model flag, rather than just changing this constant
2. why this check, what are the consequences of ignoring directory filepaths?

[jonnyhoff]

1. Changed the default model to rather be GPT3.5 because most people do not have access to GPT4.
2. The check was added to address issue https://github.com/smol-ai/developer/issues/26