Create ./volumes at cloning

Menu usually won't explicitly create the ./volumes -folder, hence Docker
will create it as owned by root. This will later cause problems for
build hooks trying to prepare directories into a now root-owned folder.

E.g. adding nextcloud later will fail with:

    Error running PreBuildHook on 'nextcloud'
    [Errno 13] Permission denied: './volumes/nextcloud'

Creating volumes as part of the initial git-clone will ensure it's owned
by the correct user.

For existing users, also add command to fix its owner when the menu is
started.

.gitignore

@@ -1,6 +1,6 @@
 #ignore data folders for containers
 /services/
-/volumes/
+/volumes/*
 /backups/
 /.tmp/*
 __pycache__

menu.sh

@@ -339,6 +339,8 @@ function do_project_checks() {
 		[ -f .project_outofdate ] && rm .project_outofdate
 		echo "Project is up to date" >&2
 	fi
+	# volumes shouldn't be owned by root, change it to the current user
+	[[ $(id -u) != "0" ]] && sudo chown $(id -u):$(id -g) volumes
 }
 
 function do_env_checks() {