Now run KG-RAG with flexible command line args!

This release has following features:

1. Added the provision to install Llama models with 'LlamaTokenizer' and 'legacy'=False option. We name this as 'method-2' in this repo.

2. Run KG-RAG using command line args in a flexible fashion.
   (A) To run in interactive mode: -i True
   Default value : False
   (B) To select gpt-models : -g gpt-4
   Default value : gpt-35-turbo
   (C) To select method-2 to run Llama : -m method-2
   Default value : method-1

3. Demo videos of README is updated using these updated command line args