improve @intlify/vite-plugin-vue-i18n/messages typing (#104)

Author: kazupon

client.d.ts

@@ -1,6 +1,8 @@
 declare module '@intlify/vite-plugin-vue-i18n/messages' {
   import { LocaleMessages } from '@intlify/core-base'
   import { VueMessageType } from 'vue-i18n'
-  const messages: LocaleMessages<VueMessageType>
+  export interface BundleLocaleMessages
+    extends LocaleMessages<VueMessageType> {}
+  const messages: BundleLocaleMessages
   export default messages
 }