Update articles/app-service/index.yml

PR review: Corrected issue flagged by Acrolinx

Author: PMEds28

articles/app-service/index.yml

@@ -4,7 +4,7 @@ title: App Service documentation
 summary: Azure App Service enables you to build and host web apps, mobile back ends, and RESTful APIs in the 
          language stack of your choice without managing infrastructure, including .NET, Java 
          (Java SE, Tomcat, and JBoss EAP), Node.js, Python, and PHP. It can also run any language stack with 
-         custom containers. I provides auto-scaling and high availability, supports both Windows and Linux, and 
+         custom containers. It provides auto-scaling and high availability, supports both Windows and Linux, and 
          enables automated deployments from GitHub, Azure DevOps, or any Git repo. Learn how to use Azure App 
          Service with our quickstarts, tutorials, and samples.