Add Valkyrie Robot

[ommmid]

Persona AI tries to stay engaged with the robotics community and open-source projects. To this end, we are making a pull request to add Valkyrie into the NVIDIA asset and its corresponding config files to Isaac Lab envs.

Related PR #2457

It will look like this in Isaac Lab documentation:

[RandomOakForest]

This is great. Thanks for submitting the PR. The team will review it.

[ommmid]

Build is failing because the USD file is not accessible. This repo holds the USD file. Please advise on how to proceed.