Merge pull request dunglas#42 from FabienSalles/patch-1

fix service name in docker-compose command

Author: dunglas

README.md

@@ -87,7 +87,7 @@ docker-compose -f docker-compose.yaml -f docker-compose.override.yaml up -d
 Inspect the installation with the following command. The requested Xdebug version should be displayed in the output.
 
 ```bash
-$ docker-compose exec php php --version
+$ docker-compose exec app php --version
 
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