Add URL parameter to enable notification of IP changes

README.md

@@ -166,6 +166,7 @@ Without TSIG authentication, the DNS server must allow updates based on IP addre
 ### Endpoints
 
 Configure one or more HTTP endpoints. If no endpoints are defined, a default endpoint at `/update` is created with standard parameter names.
+Set an empty list of names to disable a parameter.
 
 ```toml
 [[endpoints]]
@@ -176,6 +177,7 @@ ipv4 = ["myip", "ipv4", "ip4"]
 ipv6 = ["myip6", "ipv6", "ip6"]
 username = ["username", "user"]
 password = ["password", "pass", "token"]
+notify_change = ["notify_change"]
 
 [[endpoints]]
 path = "/nic/update"
@@ -185,6 +187,7 @@ ipv4 = ["myip"]
 ipv6 = ["myip6"]
 username = ["username"]
 password = ["password"]
+notify_change = []
 ```
 
 **Default accepted parameter names** (first match wins):