add loading i18n to translation.json

packages/app/resource/locales/en_US/translation.json

@@ -97,6 +97,7 @@
   "Connected": "Connected",
   "Show": "Show",
   "Hide": "Hide",
+  "Loading": "Loading...",
   "Disclose E-mail": "Disclose E-mail",
   "page exists": "this page already exists",
   "Error occurred": "Error occurred",

packages/app/resource/locales/ja_JP/translation.json

@@ -97,6 +97,7 @@
   "Connected": "接続されています",
   "Show": "公開",
   "Hide": "非公開",
+  "Loading": "読み込み中...",
   "Disclose E-mail": "メールアドレスの公開",
   "page exists": "このページはすでに存在しています",
   "Error occurred": "エラーが発生しました",

packages/app/resource/locales/zh_CN/translation.json

@@ -104,6 +104,7 @@
 	"Connected": "Connected",
 	"Show": "显示",
 	"Hide": "隐藏",
+  "Loading": "加载...",
 	"Reset": "重置",
 	"Disclose E-mail": "显示邮箱",
 	"page exists": "页面已存在",