Request: more docs on Workload-Identity-Federation

[nick-youngblut]

The gs4_auth_configure docs state:

# the preferred way to configure your own client is via a JSON file
# downloaded from Google Developers Console
# this example JSON is indicative, but fake

...but isn't Workload Identity Federation the preferred method (e.g., https://github.com/google-github-actions/deploy-cloudrun#authorization)?

It would be great to have some docs/examples on authenticating with WIF