Llama2 on EC2 tutorial using Runhouse.

[rohinb2]

What does this PR do?

Updated version of old PR.

A simple code file to stand up a Llama2 model on an A10G running in EC2. Uses the Runhouse Python library to easily provision an instance, copy code over, and serve the model.

The example is also commented with details on what different Runhouse components are doing.

Before submitting

• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
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  Pull Request section?
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• Did you make sure to update the documentation with your changes?
• Did you write any new necessary tests?

Thanks for contributing 🎉!