feat(i18n): Add Japanese to i18n (#809)

Co-authored-by: Jacky Zhao <j.zhao2k19@gmail.com>

quartz/i18n/index.ts

@@ -1,11 +1,13 @@
 import { Translation } from "./locales/definition"
 import en from "./locales/en-US"
 import fr from "./locales/fr-FR"
+import ja from "./locales/ja-JP"
 import de from "./locales/de-DE"
 
 export const TRANSLATIONS = {
   "en-US": en,
   "fr-FR": fr,
+  "ja-JP": ja,
   "de-DE": de,
 } as const