feat(locale): provide code (#2611)

src/runtime/utils/locale.ts

@@ -9,6 +9,7 @@ export type Translator = (path: string, option?: TranslatorOption) => string
 export type LocaleContext = {
   locale: Ref<Locale>
   lang: Ref<string>
+  code: Ref<string>
   t: Translator
 }
 
@@ -27,10 +28,12 @@ export function translate(path: string, option: undefined | TranslatorOption, lo
 
 export function buildLocaleContext(locale: MaybeRef<Locale>): LocaleContext {
   const lang = computed(() => unref(locale).name)
+  const code = computed(() => unref(locale).code)
   const localeRef = isRef(locale) ? locale : ref(locale)
 
   return {
     lang,
+    code,
     locale: localeRef,
     t: buildTranslator(locale)
   }