Added the full explanations in the notes section

[fertlopus]

I've added the deep explanation for the newcomers to NLP/LLMs where I cover such topics:

1. Explanation of the LLM
2. Explanation of the Semantic Search
3. Explanation of the Symmetric/Assymetric Semantic Search
4. Practical usage of the raw semantic Search via FAQ documents
5. Explanation of metrics
6. Explanation of embeddings. Difference between open-source/closed-source Embeddings models
7. RAG explanation in detail
8. RAG implementation

All was done by referencing the code owners and pointing out the DataTalks Club, Alex Grigorev and LLM Zoomcamp with the appropriate rights ownership

[alexeygrigorev]

Thank you!