Add different recipe examples to NeMo 2.0

[BoxiangW]

What does this PR do ?

Add different recipe examples to NeMo 2.0

Collection: [Note which collection this PR will affect]

Changelog

• Add specific line by line info of high level changes in this PR.

Usage

• You can potentially add a usage example below

# Add a code snippet demonstrating how to use this 

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Pre checks:

• Make sure you read and followed Contributor guidelines
• Did you write any new necessary tests?
• Did you add or update any necessary documentation?
• Does the PR affect components that are optional to install? (Ex: Numba, Pynini, Apex etc)
  • Reviewer: Does the PR have correct import guards for all optional libraries?

PR Type:

• New Feature
• Bugfix
• Documentation

If you haven't finished some of the above items you can still open "Draft" PR.

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Anyone in the community is free to review the PR once the checks have passed.
Contributor guidelines contains specific people who can review PRs to various areas.

Additional Information

• Related to # (issue)

[github-actions]

beep boop 🤖: 🚨 The following files must be fixed before merge!

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Your code was analyzed with PyLint. The following annotations have been identified:

************* Module pretraining
scripts/llm/pretraining.py:17:0: C0301: Line too long (184/119) (line-too-long)
scripts/llm/pretraining.py:80:0: C0301: Line too long (120/119) (line-too-long)
scripts/llm/pretraining.py:28:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/llm/pretraining.py:64:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/llm/pretraining.py:123:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/llm/pretraining.py:138:0: C0116: Missing function or method docstring (missing-function-docstring)

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Your code has been rated at 8.93/10

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Thank you for improving NeMo's documentation!