docs: Add doc for nano-v3

[yfw]

What does this PR do ?

Adds instructions for training nano-v3 with nemo rl.

Issues

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Additional Information

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Summary by CodeRabbit

Documentation

• Added comprehensive guide for post-training Nemotron 3 Nano model using NeMo RL.
• Includes step-by-step instructions for data preparation, repository setup, launch script configuration with required parameters, and training execution.
• Details resource requirements and environment configuration.

_{✏️ Tip: You can customize this high-level summary in your review settings.}

[coderabbitai]

📝 Walkthrough

Walkthrough

New documentation file introducing a guide for post-training the Nemotron 3 Nano model using NeMo RL. The guide covers data preparation, repository setup, launch script configuration with resource specifications, and execution instructions.

Changes

Cohort / File(s)	Summary
Documentation docs/guides/nemotron-3-nano.md	New guide file with step-by-step instructions for post-training Nemotron 3 Nano including data setup, NeMo RL repository cloning, launch script creation with environment variables and SLURM configuration, and training execution.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~5 minutes

Pre-merge checks and finishing touches

❌ Failed checks (1 inconclusive)

Check name	Status	Explanation	Resolution
Title check	❓ Inconclusive	The title 'Add doc for nano-v3' is vague and generic, using non-descriptive terms that don't convey the specific content or purpose of the documentation being added.	Use a more descriptive title that clarifies what the documentation covers, such as 'Add guide for post-training Nemotron 3 Nano with NeMo RL' to better convey the documentation's scope and purpose.

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Test Results For Major Changes	✅ Passed	PR contains only documentation changes (71-line instructional guide) with no code modifications, features, or breaking changes.

✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch yifu/nano-v3-docs

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[coderabbitai]

Actionable comments posted: 1

📜 Review details

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 669e70c and 08cc727.

📒 Files selected for processing (1)

• docs/guides/nemotron-3-nano.md

🧰 Additional context used

📓 Path-based instructions (2)

docs/**/*.md

📄 CodeRabbit inference engine (CODING_GUIDELINES.md)

Update docs/index.md when a new markdown doc is added under docs/**/*.md or a markdown file is renamed, ensuring the document appears in the most appropriate section

Files:

• docs/guides/nemotron-3-nano.md

!(**/tests/**|**/test_*.py|**/test_*.sh)

📄 CodeRabbit inference engine (CODING_GUIDELINES.md)

Add the NVIDIA copyright header to all Python files and shell scripts (excluding tests). The header should include the current year

Files:

• docs/guides/nemotron-3-nano.md

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (4)

• GitHub Check: build-container / main
• GitHub Check: Lint check
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🔇 Additional comments (3)

docs/guides/nemotron-3-nano.md (3)

1-71: Verify that docs/index.md has been updated to include this new guide.

Per the coding guidelines, when a new markdown documentation file is added under docs/**/*.md, the docs/index.md file must be updated to ensure the document appears in the most appropriate section. Since this file is not included in the review context, please confirm that it has been updated to reference docs/guides/nemotron-3-nano.md.

🔎 How to verify

Check that docs/index.md contains an entry linking to the new guide. It should appear in a section like "Guides" or similar. For example:

- [Nemotron 3 Nano Post-Training Guide](guides/nemotron-3-nano.md)

---

64-64: Clarify the ray.sub script reference.

Line 64 references ray.sub without a full path or explanation. This file is not created or described in the documentation. Please clarify whether ray.sub is:

1. A file that users should have in their repository root
2. A file provided elsewhere in the NeMo RL repository
3. Something that needs to be created by the user

Adding a brief explanation or a link to the relevant documentation would improve clarity.

---

3-71: Documentation content looks solid.

The guide provides clear step-by-step instructions for data preparation, code checkout, launch script configuration, and training execution. The bash commands are syntactically correct, the data splitting logic is sound (using head -n -1000 for training and tail -n 1000 for validation), and the SLURM configuration is well-documented with helpful placeholders.

[terrykong]

could we maybe have this at the top of this guides section so it's easy to see. also might be good to add it somewhere even higher up as well so it's easy to spot

[yfw]

Addressed in 242d9bb

[terrykong]

nice. can we also have the front page readme news bullet for nano v3 point to this doc?

[terrykong]

prob can one-line this (also since we don't tell users about pip in the main flow, so they may not even have that):

uvx --from huggingface-hub huggingface-cli download nvidia/Nemotron-3-Nano-RL-Training-Blend --repo-type dataset --local-dir=data

[yfw]

Addressed in a040a8f

[yfw]

nice. can we also have the front page readme news bullet for nano v3 point to this doc?

Updated the existing bullet point to point to these instructions.