[Feat_Add] Addition of new LLM evals metric

[tarun-aiplanet]

Beyond LLM supports, 4 evaluation metrics: Context relevancy, Answer relevancy, Groundedness, and Ground truth.

We would be looking forward to add new evaluation metric support to evaluate LLM/RAG response

• Faithfulness
• Correctness

Or any other research based metric

[adityasingh-0803]

I can work on lexical diversity

[adityasingh-0803]

@tarun-aiplanet please assign it

[tarun-aiplanet]

lexical diversity

I have never heard such metrics to evaluate LLM. Can you provide the reference of research paper. Also you were assigned for Perplexity LLM. Is that done?