Wip install scripts

mullvad-vpn-daemon/mullvad-vpn-daemon.pre-upgrade

@@ -2,7 +2,9 @@
 set -eu
 
 echo "mullvad pre-upgrade"
+# Are we running systemd?
 if which systemctl &> /dev/null && systemctl is-system-running | grep -vq offline &> /dev/null; then
+    # Is `mullvad-daemon.service` running?
     if systemctl status mullvad-daemon &> /dev/null; then
         mullvad-setup prepare-restart || true
         systemctl stop mullvad-daemon.service