💡 [REQUEST] - Tutorial on out-of-tree extension autoloading mechanism

[shink]

🚀 Describe the improvement or the new tutorial

This tutorial will help the third party extension writers better to improve seamless integration within PyTorch.

Existing tutorials on this topic

None

Additional context

No response

[svekars]

Approved. Related PR. Please follow the guidelines in the comment. Also please use this template.