allow user-defined environment variable OPENAI_API_BASE_URL

[mike2194]

OpenAI API does not necessarily have to point to https://api.openai.com/v1/.
user may wish to use something like http://ollama.local:11434/v1/

user-defined environment variable OPENAI_API_BASE_URL should override hard-coded base api url

[semidark]

That would be wonderfull. I also want to use it with my local llm setup (ollama) whicht has an openai compatible endpoint