Fix typo: App Serivce -> App Service

Author: changeworld

articles/app-service/overview.md

@@ -14,7 +14,7 @@ author: msangapu-msft
 
 Azure App Service is a platform that lets you run web applications, mobile back ends, and RESTful APIs without worrying about managing the underlying infrastructure. Think of it as a powerful web hosting service that takes care of all the heavy lifting for you, so can focus on creating great applications.
 
-App Serivce supports a variety of web stacks: .NET, Java (in Java SE, Tomcat, and JBoss flavors), Node.js, Python, and PHP, and can run them on both Windows and Linux. Or, if your app is containerized, you can just deploy it as a custom container.
+App Service supports a variety of web stacks: .NET, Java (in Java SE, Tomcat, and JBoss flavors), Node.js, Python, and PHP, and can run them on both Windows and Linux. Or, if your app is containerized, you can just deploy it as a custom container.
 
 ## Why Use Azure App Service?