Link to googleapis.dev documentation in READMEs. (#8705)

Author: busunkim96

packages/google-cloud-iam/README.rst

@@ -14,7 +14,7 @@ Python Client for IAM API (`Alpha`_)
    :target: https://python-compatibility-tools.appspot.com/one_badge_target?package=git%2Bgit%3A//github.com/googleapis/google-cloud-python.git%23subdirectory%3Diam
 .. _Alpha: https://github.com/googleapis/google-cloud-python/blob/master/README.rst
 .. _IAM API: https://cloud.google.com/iam
-.. _Client Library Documentation: https://googleapis.github.io/google-cloud-python/latest/iam/index.html
+.. _Client Library Documentation: https://googleapis.dev/python/iam/latest
 .. _Product Documentation:  https://cloud.google.com/iam
 
 Quick Start
@@ -30,7 +30,7 @@ In order to use this library, you first need to go through the following steps:
 .. _Select or create a Cloud Platform project.: https://console.cloud.google.com/project
 .. _Enable billing for your project.: https://cloud.google.com/billing/docs/how-to/modify-project#enable_billing_for_a_project
 .. _Enable the IAM API.:  https://console.cloud.google.com/flows/enableapi?apiid=iam
-.. _Setup Authentication.: https://googleapis.github.io/google-cloud-python/latest/core/auth.html
+.. _Setup Authentication.: https://googleapis.dev/python/google-api-core/latest/auth.html
 
 Installation
 ~~~~~~~~~~~~