update en-US

lib/locales/en-US/translation.json

@@ -294,6 +294,7 @@
         "tab_switch": "Save tab-switching in the browser",
         "save_edit": "Save edit tab and history tab switching in the browser and make it object for forward/back command of the browser.",
         "by_invalidating": "By invalidating, you can make page transition as the only object for forward/back command of the browser.",        
-        "Custom CSS": "Custom CSS"
+        "Custom CSS": "Custom CSS",
+        "write_CSS": "You can write CSS that is applied to whole system."
       }
 }