Update I18N.md

Fixed typo in localization.

I18N.md

@@ -18,7 +18,7 @@ genie-toolkit
     └── en/timers.genie         -> zh-tw/timers.genie
 └── lib
     └── i18n
-        └── american-english.js -> trafitional-chinese.js
+        └── american-english.js -> traditional-chinese.js
 ```
 
 Add the option for the target language in `lib/i18n/index.js`.