Refactor Gradio interface layout and update slider parameters for improved user experience

Add optional API key support in settings and update text continuation endpoint

Update Dockerfile to run Gradio application and expose port 7860

Add Gradio interface for GPT text continuation and update requirements

Add optional API key parameter to generate_with_openai function

Implement FastAPI app with text continuation endpoint and error handling

Add OpenAI service for text generation and update requirements

Add configuration settings and update requirements for pydantic_settings

Add schemas for text continuation request and response

Add initial project files including FastAPI app, Dockerfile, requirements, and .gitignore

initial commit