Update README.md

Author: glibnub

README.md

@@ -12,6 +12,6 @@ urlFragment: php-docs-hello-world
 
 This sample demonstrates a tiny Hello World PHP app for [App Service](https://docs.microsoft.com/azure/app-service).
 
-# Contributing
+## Contributing
 
 This project has adopted the [Microsoft Open Source Code of Conduct](https://opensource.microsoft.com/codeofconduct/). For more information see the [Code of Conduct FAQ](https://opensource.microsoft.com/codeofconduct/faq/) or contact [[email protected]](mailto:[email protected]) with any additional questions or comments.