Improved readme content and links. (#1196)

Co-authored-by: lastnameholiu <[email protected]>

README.md

@@ -1,11 +1,65 @@
 # Maven Plugins for Azure Services
-This repository contains all Maven plugins for Microsoft Azure services. A complete list of all plugins is shown as below. Visit our [Wiki](https://github.com/microsoft/azure-maven-plugins/wiki) for detailed documentation.
+
+This repository contains all Maven plugins for Microsoft Azure services. 
+
+* [Plugins](#plugins)
+* [Authentication](#Authentication)
+* [Common Configurations](#Common-Configurations)
+* [CI/CD in Azure DevOps](#CI-CD-in-Azure-DevOps)
+* [Feedback and Questions](#Feedback-and-Questions)
+* [Contributing](#Contributing)
+* [Telemetry](#Telemetry)
+
+For more information on authentication, common configurations, CI CD, and general plugin documentation, [see the Wiki](https://github.com/microsoft/azure-maven-plugins/wiki).
+
+## Plugins
 
 Maven Plugin | Maven Central Version | Build Status
 ---|---|---
 [Maven Plugin for Azure Web Apps](./azure-webapp-maven-plugin/README.md) | [![Maven Central](https://img.shields.io/maven-central/v/com.microsoft.azure/azure-webapp-maven-plugin.svg)](http://search.maven.org/#search%7Cga%7C1%7Cg%3A%22com.microsoft.azure%22%20AND%20a%3A%22azure-webapp-maven-plugin%22) | [![AppVeyor Webapp Plugin](https://ci.appveyor.com/api/projects/status/0vr4svfgl9u3rcaw/branch/develop?svg=true)](https://ci.appveyor.com/project/xscript/azure-maven-plugins-xt3xm)
-[Maven Plugin for Azure Functions](./azure-functions-maven-plugin/README.md) | [![Maven Central](https://img.shields.io/maven-central/v/com.microsoft.azure/azure-functions-maven-plugin.svg)](http://search.maven.org/#search%7Cga%7C1%7Cg%3A%22com.microsoft.azure%22%20AND%20a%3A%22azure-functions-maven-plugin%22) | [![AppVeyor Function Plugin](https://ci.appveyor.com/api/projects/status/5jti4qwh0j4ekh72/branch/develop?svg=true)](https://ci.appveyor.com/project/xscript/azure-maven-plugins-vvy0i)
-[Maven Plugin for Azure Spring Cloud](./azure-spring-cloud-maven-plugin/README.md) | [![Maven Central](https://img.shields.io/maven-central/v/com.microsoft.azure/azure-spring-cloud-maven-plugin.svg)](http://search.maven.org/#search%7Cga%7C1%7Cg%3A%22com.microsoft.azure%22%20AND%20a%3A%22azure-spring-cloud-maven-plugin%22) | 
+[Maven Plugin for Azure Functions](https://github.com/microsoft/azure-maven-plugins/wiki/Azure-Functions) | [![Maven Central](https://img.shields.io/maven-central/v/com.microsoft.azure/azure-functions-maven-plugin.svg)](http://search.maven.org/#search%7Cga%7C1%7Cg%3A%22com.microsoft.azure%22%20AND%20a%3A%22azure-functions-maven-plugin%22) | [![AppVeyor Function Plugin](https://ci.appveyor.com/api/projects/status/5jti4qwh0j4ekh72/branch/develop?svg=true)](https://ci.appveyor.com/project/xscript/azure-maven-plugins-vvy0i)
+[Maven Plugin for Azure Spring Cloud](https://github.com/microsoft/azure-maven-plugins/wiki/Azure-Spring-Cloud) | [![Maven Central](https://img.shields.io/maven-central/v/com.microsoft.azure/azure-spring-cloud-maven-plugin.svg)](http://search.maven.org/#search%7Cga%7C1%7Cg%3A%22com.microsoft.azure%22%20AND%20a%3A%22azure-spring-cloud-maven-plugin%22) | 
+
+
+## Authentication
+
+All the Azure Maven plugins share the same authentication logic. There are 4 authentication methods by priority order:
+
+1. [Service Principles in plugin configuration](https://github.com/microsoft/azure-maven-plugins/wiki/Authentication#service-principles-in-plugin-configuration)
+1. [Service Principles in settings.xml](https://github.com/microsoft/azure-maven-plugins/wiki/Authentication#service-principles-in-settings.xml) (Recommended for production use)
+1. [Maven Plugin for Azure Account](https://github.com/microsoft/azure-maven-plugins/wiki/Authentication#maven-plugin-for-azure-account) (Default if no other method are used)
+1. [Azure CLI](https://github.com/microsoft/azure-maven-plugins/wiki/Authentication#azure-cli)
+
+For example, if you have not only Service Principles configured in your plugin configuration, but also Azure CLI installed and logged in, the Azure Maven plugins will use the Service Principles in your plugin configuration.
+
+If no credential found, Azure Maven plugins will automatically log you in with the third method like OAuth or DeviceLogin provided by Maven Plugin for Azure Account.
+
+### AuthType (since Web App 1.9.0)
+You can specify which authentication method to use with <authType> in Maven configuration, the default value is auto, and here are all the valid values:
+
+* service_principal
+    * Will use credential specified in plugin configuration or Maven settings.xml, this is also the first priority authentication method in auto
+* azure_auth_maven_plugin
+    * Will use credential provided by Azure Auth Maven Plugin, it will first consume existing secret files, and will guide you auth with Oath or Device Login if you hadn't authenticated with Auth Maven Plugin before.
+* azure_cli
+    * Will use credential provided by Azure CLI, this could also be used in Azure Cloud Shell.
+* auto
+    * Will try all the auth methods in the following sequence: service_principal, azure_auth_maven_plugin(existing secret files), azure_cli, azure_auth_maven_plugin
+
+> Maven plugin will only try the specific authentication method (except auto) if <AuthType> is set in configuration.
+
+See the [Authentication](https://github.com/microsoft/azure-maven-plugins/wiki/Authentication) section in our wiki for more information.
+
+## Common Configurations
+The three Maven Plugins for Azure Web App/Functions/Spring Cloud support below configuration properties.
+
+| Property | Required | Description | Version |
+| --- | --- | --- | --- | 
+| \<subscriptionId> | false	| Specifies the target subscription.<br>Use this setting when you have multiple subscriptions in your authentication file. | WebApp: 0.1.0<br>Function: 0.1.0<br>Spring: 1.0.0 |
+| \<allowTelemetry> | false | Specifies whether to allow this plugin to send telemetry data; default value is true. | 	WebApp: 0.1.0 <br> Function: 0.1.0 <br> Spring: 1.0.0 |
+| \<auth> | false | Specifies auth configuration. For more info, please refer to [here.](https://github.com/microsoft/azure-maven-plugins/wiki/Authentication#authentication) | WebApp:0.1.0 <br> Function:0.1.0 | 
+ | \<authType> | false | Specifies which authentication method to use, default value is auto. For more infos, please refer to [here.](https://github.com/microsoft/azure-maven-plugins/wiki/Authentication#authtype) | WebApp:1.9.0 | 
+ | \<skip> | false | Specifies whether to skip execution. Default value is false. | WebApp: 0.1.4 <br> Function: 0.1.0 | 
 
 ## Feedback and Questions
 To report bugs or request new features, file issues on [Issues](https://github.com/microsoft/azure-maven-plugins/issues). Or, ask questions on [Stack Overflow with tag azure-java-tools](https://stackoverflow.com/questions/tagged/azure-java-tools).