add loading indicator

src/plain-text/Toast.ts

@@ -0,0 +1,11 @@
+export interface ToastText {
+  error: string;
+}
+
+export const toastZhCn: ToastText = {
+  error: '获取失败',
+};
+
+export const toastEnUs: ToastText = {
+  error: 'Request Failed',
+};