Effectively manage API usability changes

[miladm]

📚 Documentation

Context: PyTorch/XLA is going through a heavy set of changes to its API surface area to make it easier for the users to take advantage of this technology.

While we go through this exercise in the next few quarters, it's crucial to ensure users easily follow the changes. To this end, I propose the following two tasks:

Task1: maintain a GH table that outlines the following information for any user-facing API/env-variable change. Maintain a table with these columns:

• New API Name
• Release version with new API
• Nighly date with new API
• Old API Name
• Last release version supporting the old API
• A RFC GH link explaining the API change

I suggest we pin this page on the GH Issue section for easy access by users.

Task2: update the deprecation logic to reflect more information. The following information should be included in the messaging:

• old_name last release version support
• Link to the GH page that tracks Task1

cc @will-cromar @JackCaoG