meta(docs): Add systemd example files

examples/update-firewall-source.service.example

@@ -0,0 +1,12 @@
+[Unit]
+Description=firewalld direct rules generator
+After=multi-user.target
+
+[Service]
+Type=oneshot
+RemainAfterExit=no
+Environment='PATH=/usr/local/sbin:/usr/local/bin:/usr/bin' 'UFS_LOGLEVEL=INFO'
+ExecStart=/opt/miniconda3/envs/update-firewall-source/bin/python /opt/python/update-firewall-source/dev/update-firewall-source.py
+
+[Install]
+WantedBy=multi-user.target