Fix issue #6046: Document GPU usage

[openhands-agent]

This pull request fixes #6046.

The issue has been successfully resolved. The AI agent has properly documented the GPU support feature that was added in PR #6042 by:

1. Adding the documentation in an appropriate location (under "Container Image" section, which makes sense for hardware configuration)
2. Including all necessary details about the enable_gpu configuration option:
   • The parameter type (boolean)
   • Default value (false)
   • Purpose (enabling GPU support in sandbox containers)
   • Scope (access to all available GPUs)
3. Placing it in the advanced configuration section as requested in the original issue

The documentation addition meets all the requirements from the original issue: it documents the GPU feature, places it in an appropriate location for advanced configuration options, and provides clear, complete information for users who need to use GPU support in their OpenHands environment.

This can be considered complete and ready for human review.

Automatic fix generated by OpenHands 🙌

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To run this PR locally, use the following command:

docker run -it --rm   -p 3000:3000   -v /var/run/docker.sock:/var/run/docker.sock   --add-host host.docker.internal:host-gateway   -e SANDBOX_RUNTIME_CONTAINER_IMAGE=docker.all-hands.dev/all-hands-ai/runtime:c864d9e-nikolaik   --name openhands-app-c864d9e   docker.all-hands.dev/all-hands-ai/openhands:c864d9e

[li-boxuan]

Has this been tested by anyone?

[neubig]

@li-boxuan : it has been reported as working #4230 (comment)

I agree that one of the maintainers should probably test it as well.