Add notify-on-dhcp-lease script

doc/notify-on-dhcp-lease.md

@@ -0,0 +1,47 @@
+Notify on a new DHCP lease 
+==========================
+
+[◀ Go back to main README](../README.md)
+
+> ℹ️ **Info**: This script can not be used on its own but requires the base
+> installation. See [main README](../README.md) for details.
+
+Description
+-----------
+
+This script is run from scheduler periodically, checking for LTE state changes.
+
+### Sample notification
+
+![notify-on-dhcp-lease notification](notify-on-dhcp-lease.d/notification.avif)
+
+Requirements and installation
+-----------------------------
+
+Just install the script:
+
+    $ScriptInstallUpdate notify-on-dhcp-lease;
+
+Requires lease-script installed:
+
+    $ScriptInstallUpdate lease-script;
+
+Configuration
+-------------
+
+The configuration goes to `global-config-overlay`, there are no additional parameters.
+
+Also notification settings are required for
+[e-mail](mod/notification-email.md),
+[matrix](mod/notification-matrix.md) and/or
+[telegram](mod/notification-telegram.md).
+
+See also
+--------
+
+* [Notify on RouterOS update](check-routeros-update.md)
+* [Install LTE firmware upgrade](unattended-lte-firmware-upgrade.md)
+
+---
+[◀ Go back to main README](../README.md)  
+[▲ Go back to top](#top)