Adds section for Sim2Real resources with available/open-source code

[louislelay]

Description

This PR adds a new subsection under the Sim2Real deployment guide to highlight external resources featuring publicly available or open-source implementations.

Included links:

• Isaac Sim policy deployment tutorial (official docs)
• NVIDIA Technical Blog post on Spot locomotion with Isaac Lab
• Kinova Gen3 Sim2Real deployment repo
• UW Robot Learning's WheeledLab project

This should help users discover real-world examples and accelerate their own deployment pipelines.

Type of change

• This change requires a documentation update

Screenshots

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Checklist

• I have run the pre-commit checks with ./isaaclab.sh --format
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• [N/A] I have added tests that prove my fix is effective or that my feature works
• [N/A] I have updated the changelog and the corresponding version in the extension's config/extension.toml file
• I have added my name to the CONTRIBUTORS.md or my name already exists there