docs: fix 5 docstring errors in Gemma3nTextConfig (typos, grammar, formatting)

[RudrenduPaul]

What does this PR do?

Fixes five documentation errors in the Gemma3nTextConfig docstring in modular_gemma3n.py (and the generated configuration_gemma3n.py):

1. Typo: "emebeddings" → "embeddings" in hidden_size_per_layer_input
2. Incomplete sentence: altup_active_idx description was cut off at "or correct" — completed to "or correct the active prediction."
3. Grammar: "should be make" → "should make" in altup_num_inputs
4. Grammar: "number of layer" → "number of layers" in num_kv_shared_layers
5. Formatting: Added missing backticks around type annotations for laurel_rank and activation_sparsity_pattern to match HF docstring conventions used consistently throughout the file

Both the modular source file (modular_gemma3n.py) and the generated configuration file (configuration_gemma3n.py) are updated in sync.

Before submitting

• This PR fixes a typo or improves the docs (you can dismiss the "Test" section below).
• Did you read the contributor guideline, Pull Request section?
• Was this discussed/approved via a Github issue or the forum? Please add a link to it if that's the case.
• Did you make sure to update the documentation with your changes? Here are the documentation guidelines, and here are tips on formatting docstrings.
• Did you write any new necessary tests?

Note to maintainers: These are purely documentation corrections — no logic changes. The modular file is the source of truth; the generated file was updated by hand to match (identical diff in both files). Running make fix-repo will confirm the generated file is in sync.

AI disclosure

• AI-assisted contribution (Claude Code used to identify and draft fixes; all changes reviewed and validated by Rudrendu Paul)
• I confirm this is NOT a pure code agent PR — the human submitter (Rudrendu Paul) has reviewed every changed line

Who can review?

@stevhliu @zucchini-nlp

[github-actions]

[For maintainers] Suggested jobs to run (before merge)

run-slow: gemma3n

[Rocketknight1]

Yep, looks good!

[HuggingFaceDocBuilderDev]

The docs for this PR live here. All of your documentation changes will be reflected on that endpoint. The docs are available until 30 days after the last update.