add zh-CN/TW strings

[dockfries]

btw, this should be a typo problem, settigs_custom_game_exe_label -> settings_custom_game_exe_label.
this pr, I still use the previous typo.

Another issue is that language region code variants are ignored.
For Chinese, it will not be able to match zh-CN/zh-TW, but it will match zh and then fallback to en.

  /**
   * Language codes to lookup, given set language is 'en-US'
   * 'all' --> ['en-US', 'en', 'dev'],
   * 'currentOnly' --> 'en-US',
   * 'languageOnly' --> 'en'
   * @default 'all'
   */
  load?: 'all' | 'currentOnly' | 'languageOnly';