[Bug] V3 Hyperparameter Tuning Pipeline page labelled "Download Data" in navigation due to missing title cell

**PySDK Version**
- [ ] PySDK V2 (2.x)
- [ x] PySDK V3 (3.x)

**Describe the bug**
The [V3 Hyperparameter Tuning Pipeline example](https://sagemaker.readthedocs.io/en/stable/v3-examples/ml-ops-examples/v3-hyperparameter-tuning-example/v3-hyperparameter-tuning-pipeline.html) notebook is missing a title markdown cell. The notebook's first cell is a code cell (imports), so the first markdown heading `### Download Data`is picked up as the page label in the readthedocs navigation sidebar, causing the page to appear as "Download Data" rather than "V3 Hyperparameter Tuning Pipeline".

**To reproduce**
1. Navigate to the [readthedocs page](https://sagemaker.readthedocs.io/en/stable/v3-examples/ml-ops-examples/v3-hyperparameter-tuning-example/v3-hyperparameter-tuning-pipeline.html)
2. Observe the sidebar navigation label for this page

**Expected behavior**
The page should be labelled "V3 Hyperparameter Tuning Pipeline" (or similar) in the navigation sidebar, not "Download Data".

**Screenshots or logs**

**System information**
A description of your system. Please provide:
- **SageMaker Python SDK version**:
- **Framework name (eg. PyTorch) or algorithm (eg. KMeans)**:
- **Framework version**:
- **Python version**:
- **CPU or GPU**:
- **Custom Docker image (Y/N)**:

**Additional context**
Fix: add a title markdown cell as the first cell in doc/source/v3-examples/ml-ops-examples/v3-hyperparameter-tuning-example/v3-hyperparameter-tuning-pipeline.ipynb:

```
{
"cell_type": "markdown",
"id": "intro",
"metadata": {},
"source": ["# V3 Hyperparameter Tuning Pipeline"]
}
```

Abre doc/source/v3-examples/ml-ops-examples/v3-hyperparameter-tuning-example/v3-hyperparameter-tuning-pipeline.ipynb e inspecciona su primera celda y la página de Read the Docs renderizada. Añade la celda de título introductoria que falta para que la página aparezca con la etiqueta “V3 Hyperparameter Tuning Pipeline” en lugar de “Download Data”, y luego verifica que el notebook se renderice con la etiqueta de navegación corregida.

Escrito por el modelo de indexación a partir del texto del issue.