Adding end-to-end llama chatbot recipe using Retrieval Augmented Fine Tuning (RAFT)

[wukaixingxp]

What does this PR do?

In this tutorial, we demonstrated how to use official documents to build a Llama Chatbot for Llama users using Retrieval Augmented Fine Tuning (RAFT).

Feature/Issue validation/testing

Please describe the tests that you ran to verify your changes and relevant result summary. Provide instructions so it can be reproduced.
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• Test A
  Logs for Test A

• Test B
  Logs for Test B

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• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
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Thanks for contributing 🎉!

[HamidShojanazeri]

thanks @wukaixingxp for the updates on the PR. Added round1 comments will add the second round as you are working on the first round.

[HamidShojanazeri]

thanks @wukaixingxp LGTM, will merge, and we can have a follow up PR to add more into the guide.