update en-US

lib/locales/en-US/translation.json

@@ -273,7 +273,8 @@
  },
 
   "markdown_setting": { 
-    "markdown_rendering": "You can change Markdown rendering settings."
+    "markdown_rendering": "You can change Markdown rendering settings.",
+    "validate Line Break": "Validate Line Break"
 
  }
 }