renderer: add vuetify localization

src/renderer/plugins/vuetify.js

@@ -1,7 +1,13 @@
 import { createVuetify } from 'vuetify/dist/vuetify'
+import { ko, en } from 'vuetify/locale'
 
 export default createVuetify({
   icons: {
     iconfont: 'mdi'
+  },
+  locale: {
+    messages: { ko, en },
+    defaultLocale: 'en',
+    fallbackLocale: 'en'
   }
 })