Add docker compose override file for RTX deployments

[jdye64]

Description

Provides a Docker compose override file for RTX deployments. This allows for specific NIM versions to be deployed that are optimized to save VRAM usage on RTX cards.

This allows nv-ingest to be deployed like so ...

docker compose -f docker-compose.yaml -f docker-compose.rtx.yaml up

• Note as of writing the actual NIM URLs have not been determined and this is serving more as a placeholder for when those URLs are ready.

Checklist

• I am familiar with the Contributing Guidelines.
• New or existing tests cover these changes.
• The documentation is up to date with these changes.