Documentation update for the config of dial tone on the second call, REF 14115

schemas/uci/asterisk.json

@@ -480,6 +480,13 @@
                     "required": "",
                     "default": "uk",
                     "description": "Flash-hook for different specs,'etsi'= R0-R5, 'uk'= R,R4,R5 "
+                },
+                {
+                    "name": "second_dial_tone",
+                    "type": "string",
+                    "required": "",
+                    "default": "special",
+                    "description": "Dial tone for the second dialing after flash-hook "
                 }
             ]
         },