Added timer and service, will update install script later

borg/systemd/backup.service

@@ -0,0 +1,8 @@
+[Unit]
+Description=Backup service using borg
+Type=oneshot
+
+[Service]
+ExecStart=/opt/borg/bin/backup
+Wants=multi-user.target
+

borg/systemd/backup.timer

@@ -0,0 +1,10 @@
+[Unit]
+Description= Run backup every day at 4am
+
+[Timer]
+OnCalendar=*-*-* 4:00:00
+RandomizedDelaySec=15m
+Unit=backup.service
+
+[Install]
+WantedBy=timers.target