Task: fix readme docker yml to yaml (#381)

README.md

@@ -35,7 +35,7 @@ You don't need to have a PHP environment with composer installed.
     `cd my-project/`
 1. Part of the new project is a docker compose file
     * Run `` echo `id -u`:`id -g` `` to retrieve your local user and group id
-    * Open the `docker-compose.yml` file in an editor, uncomment all the `user: '1000:1000'` lines and update the ids if necessary
+    * Open the `docker-compose.yaml` file in an editor, uncomment all the `user: '1000:1000'` lines and update the ids if necessary
     * Start the needed services with `docker-compose up -d`
 1. Install pimcore and initialize the DB
     `docker-compose exec php vendor/bin/pimcore-install --mysql-host-socket=db --mysql-username=pimcore --mysql-password=pimcore --mysql-database=pimcore`