az batch pool | example links need to be escaped in reference content

### Describe the bug

Please see similar issue for Core command subgroup `az batch account`: [Azure/azure-cli GH issue #29622](https://github.com/Azure/azure-cli/issues/29622)

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### Describe the bug

Please escape these example links in source code so they are corrected in MicrosoftDocs/azure-docs-cli autogenerated reference content.

Example links are needed in reference examples, but they should to be escaped so that GitHub does not treat them like live URLs.

### List of Extension links that need escaped:
|File name | Build error |
|-|-|
| latest/docs-ref-autogen/batch/pool.yml | Link 'https://learn.microsoft.com/azure/virtual-' points to a learn site page that doesn't exist. Check the path or URL and update the link. |

### Related command

az batch pool