Updated readme for allow-no-subscriptions input support (#79)

* Updated readme for no-subscriptions support

* Minor changes

* Updated readme

README.md

@@ -14,7 +14,7 @@ Get started today with a [free Azure account](https://azure.com/free/open-source
 
 With the Azure login Action, you can automate your workflow to do an Azure login using [Azure service principal](https://docs.microsoft.com/azure/active-directory/develop/app-objects-and-service-principals) and run Azure CLI and Azure PowerShell scripts.
 
-By default, the action only logs in with the Azure CLI (using the `az login` command). To log in with the Az PowerShell module, set `enable-AzPSSession` to true.
+By default, the action only logs in with the Azure CLI (using the `az login` command). To log in with the Az PowerShell module, set `enable-AzPSSession` to true. To login to Azure tenants without any subscriptions, set the optional parameter `allow-no-subscriptions` to true.
 
 This repository contains GitHub Action for [Azure Login](https://github.com/Azure/login/blob/master/action.yml).
 
@@ -130,6 +130,29 @@ The following steps describe how to create the service principal, assign the rol
 
 NOTE: to manage service principals created with `az ad sp create-for-rbac`, visit the [Azure portal](https://portal.azure.com), navigate to your Azure Active Directory, then select **Manage** > **App registrations** on the left-hand menu. Your service principal should appear in the list. Select a principal to navigate to its properties. You can also manage role assignments using the [az role assignment](https://docs.microsoft.com/cli/azure/role/assignment?view=azure-cli-latest) command.
 
+## Support for using `allow-no-subscriptions` flag with az login
+
+Capability has been added to support access to tenants without subscriptions. This can be useful to run tenant level commands, such as `az ad`. The action accepts an optional parameter `allow-no-subscriptions` which is `false` by default.
+
+```yaml
+# File: .github/workflows/workflow.yml
+
+on: [push]
+
+name: AzureLoginWithNoSubscriptions
+
+jobs:
+
+  build-and-deploy:
+    runs-on: ubuntu-latest
+    steps:
+
+    - uses: azure/login@v1
+      with:
+        creds: ${{ secrets.AZURE_CREDENTIALS }}
+        allow-no-subscriptions: true
+```
+
 # Contributing
 
 This project welcomes contributions and suggestions.  Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.opensource.microsoft.com.