[BUG] - Links to DTensor resources are broken

[astefanutti]

Add Link

https://pytorch.org/tutorials/beginner/dist_overview.html

Describe the bug

DTensor has moved to the public namespace and references need to be updated accordingly.

Describe your environment

N/A

cc @svekars @brycebortree @sekyondaMeta @wconstab @osalpekar @H-Huang @kwen2501