kamailio-kemi-framework: docs for core KSR.hdr.rmappend(...)

kamailio-kemi-framework/docs/core.md

@@ -762,6 +762,20 @@ Example:
 KSR.hdr.remove("X-My-Hdr");
 ```
 
+### KSR.hdr.rmappend(...) ###
+
+`int KSR.hdr.rmappend(str "hrm", str "hadd")`
+
+Remove all the headers with the name `hrm` and append `hadd`. The value for
+`hadd` must include header name name and ending `\r\n`. This function is a
+a wrapper for `KSR.hdr.remove("hrm")` and `KSR.hdr.append("hadd")`.
+
+Example:
+
+```
+KSR.hdr.remove("X-My-Hdr", "X-My-Hdr: abc\r\n");
+```
+
 ### KSR.hdr.is_present(...) ###
 
 `int KSR.hdr.is_present(str "hdrval")`