inventory, roles, config, docs: update all files to refactor the ansible variables structure

config/services/systemd/fw/ddns/ddns.timer.j2

@@ -0,0 +1,10 @@
+[Unit]
+Description=Run DDNS update service every 5 minutes
+
+[Timer]
+OnBootSec=1min
+OnUnitActiveSec=5min
+Persistent=true
+
+[Install]
+WantedBy=timers.target