Clarify support policy in Identity readme (#16886)

Some of the clarity around support policy did not get added to the Identity readme like they were added in other packages. This PR fixes that problem

sdk/identity/identity/README.md

@@ -13,6 +13,15 @@ Key links:
 
 ## Getting started
 
+### Currently supported environments
+
+- [LTS versions of Node.js](https://nodejs.org/about/releases/)
+   - **Note:** If your application runs on Node.js v8 or lower and you cannot upgrade your Node.js version to latest stable version, then pin your `@azure/identity` dependency to version 1.1.0.
+- Latest versions of Safari, Chrome, Edge, and Firefox.
+   - **Note**: Among the different credentials exported in this library, `InteractiveBrowserCredential` is the only one that is supported in the browser.
+
+See our [support policy](https://github.com/Azure/azure-sdk-for-js/blob/main/SUPPORT.md) for more details.
+
 ### Install the package
 
 Install Azure Identity with `npm`:
@@ -26,12 +35,6 @@ npm install --save @azure/identity
 - An [Azure subscription](https://azure.microsoft.com/free/).
 - Optional: The [Azure CLI][azure_cli] and/or [Azure PowerShell][azure_powershell] can also be useful for authenticating in a development environment and managing account roles.
 
-#### Supported Node.js versions
-
-This version of `@azure/identity` supports stable (even numbered) versions of Node.js starting from v10. While it may run in Node.js v8, no support is guaranteed.
-
-> **Note:** If your application runs on Node.js v8 or lower, we strongly recommend you to upgrade your Node.js version to latest stable version or pin your `@azure/identity` dependency to version 1.1.0.
-
 ### When to use @azure/identity
 
 The credential classes exposed by `@azure/identity` are focused on providing the most straightforward way to authenticate the Azure SDK clients locally, in your development environments, and in production. We aim for simplicity and reasonable support of the authentication protocols to cover most of the authentication scenarios possible on Azure. We're actively expanding to cover more scenarios. For a full list of the credentials offered, see the [Credential Classes](#credential-classes) section.