Additional hooks - Using an own install script

[marcoschierhorn]

Again, thanks for your great work :-)
I'm trying to use my own startup shell script and use it to rm the shopware.yaml file to deploy my own version.
I've put it under /rootfs/etc/shopware/scripts/on-install and also put the shopware.yaml file under /rootfs/etc/shopware/config/packages. But unfortunately both files disappear in the container when I'm using docker-composer up.
Am I missing something? In the Dockerfile I can see that you are copying /rootfs to the root of the container, but it seems that it doesn't use the rootfs I have changed.