documentation: add the missed param write_to_system into ntp

docs/configuration/ntp/index.md

@@ -14,7 +14,8 @@ synchronization is not possible.
     "server": "time.apple.com",
     "server_port": 123,
     "interval": "30m",
-    
+    "write_to_system": false
+
     ... // Dial Fields
   }
 }
@@ -45,6 +46,12 @@ Time synchronization interval.
 
 30 minutes is used by default.
 
+#### write_to_system
+
+Write time to system.
+
+false is used by default.
+
 ### Dial Fields
 
 See [Dial Fields](/configuration/shared/dial/) for details.

docs/configuration/ntp/index.zh.md

@@ -13,8 +13,9 @@
     "server": "time.apple.com",
     "server_port": 123,
     "interval": "30m",
-    
-    ... // 拨号字段
+    "write_to_system": false
+
+    ... // Dial Fields
   }
 }
 
@@ -44,6 +45,12 @@ NTP 服务器端口。
 
 默认使用 30 分钟。
 
+#### write_to_system
+
+写入系统时间。
+
+默认不写入。
+
 ### 拨号字段
 
 参阅 [拨号字段](/zh/configuration/shared/dial/)。