Add RunLLM chat widget to TorchMetrics

[likawind]

What does this PR do?

Fixes Issue N/A

This PR adds RunLLM chat widget to torch metrics. The codespace has trouble building the sphnix so would appreciate if Lightning AI can provide guidance testing the change.

Before submitting

• [ N/A ] Was this discussed/agreed via a Github issue? (no need for typos and docs improvements)
• Did you read the contributor guideline, Pull Request section?
• [ N/A ] Did you make sure to update the docs?
• [ N/A ] Did you write any new necessary tests?

PR review

Lighting AI team are welcomed reviewing the PR as the goal is to enhance TorchMetric's documentation website :) .

Did you have fun?

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📚 Documentation preview 📚: https://torchmetrics--2732.org.readthedocs.build/en/2732/

[likawind]

Thanks for reviewing @Borda ! May I get your help having the 2nd person reviewing this PR? I'd also like to get some insight on this check failure as I don't think it's related to this change

[SkafteNicki]

LGTM :)