Add systemd unit/timer for the cleanup tool (#210)

* add systemd service for the cleanup script

* add systemd timer for the cleanup service

linx-cleanup.service

@@ -0,0 +1,12 @@
+[Unit]
+Description=Self-hosted file/code/media sharing (expired files cleanup)
+After=network.target
+
+[Service]
+User=linx
+Group=linx
+ExecStart=/usr/bin/linx-cleanup
+WorkingDirectory=/srv/linx/
+
+[Install]
+WantedBy=multi-user.target

linx-cleanup.timer

@@ -0,0 +1,8 @@
+[Unit]
+Description=Run linx-cleanup every hour
+
+[Timer]
+OnUnitActiveSec=1h 
+
+[Install]
+WantedBy=timers.target