Need new documents based on Workload identity instead of deprecated Pod identity

[JoeyC-Dev]

Is your feature request related to a problem? Please describe.
Pod identity has been deprecated, but the documents are still using Pod identity as the steps:

It looks like workload identity is supposed as I have seen this comment: #1521 (comment)

And there is a .md file mentioning this:
https://github.com/Azure/application-gateway-kubernetes-ingress/blob/master/docs/setup/install.md

Trying to edit, but no where to contribute:

I have found branch gh-pages, but it looks like bot editing (or need to follow some other process) and I don't know if I should do a PR on this:

Describe the solution you'd like
Need new document based on workload identity.

Also, I am curious that if using az aks enable-addons --addons ingress-appgw, will the AGIC being set up under "Pod identity" or "Workload identity"?