This pull request upgrades the project to support all OpenAI models, including GPT-4o-mini (128K context window), by updating llama-index and adapting the code accordingly.

Changes:

• Upgraded llama-index from 0.9.48 to 0.12.22 for broader model compatibility.
• Installed llama-index-experimental==0.5.4 to improve indexing and querying.
• Updated Python files (main.py, pdf.py, prompts.py, note_engine.py) to work with the upgraded library.
• Updated requirements.txt with only essential dependencies.
• Modified README.md to reflect the new setup and .env configuration.

Why?

• The previous version didn’t support gpt-4o-mini, limiting model options.
• This upgrade allows users to leverage the 128K context window for better performance.
• Ensures compatibility with all OpenAI models, including gpt-3.5-turbo.

Testing:

• Successfully tested with GPT-4o-mini and GPT-3.5-turbo.

This update makes the project more flexible, future-proof, and efficient.