Fix markdown ordered lists counter reset

[rbren]

This PR fixes the issue where markdown ordered lists were not incrementing numbers correctly. The fix adds a counterReset: "list-item" style to ensure each ordered list starts with a fresh counter.

Changes:

• Added style={{ counterReset: "list-item" }} to the ordered list component
• Maintains existing spacing and styling

Before:
All list items showed as "1." instead of incrementing numbers.

After:
List items now correctly show as "1.", "2.", "3.", etc.

Note on Tests:
Some tests are failing due to missing i18n declarations, which is a separate issue with the test environment setup. These failures are unrelated to our changes since we only modified the markdown list component and its styling.

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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:fd6820f-nikolaik   --name openhands-app-fd6820f   docker.all-hands.dev/all-hands-ai/openhands:fd6820f

[rbren]

Whoops this was a demo