Attempt to add FR as French; need help to understand my mistake before PR

I basically replicated what @GermanHeim did with Spanish but when I generate my website, only the next.js part is translated, and what is in lang.js js ignored. So before doing my PR I would like to make it work 😉

• my line 7 in blog.config is now: lang: 'fr-CA', // ['en-US', 'zh-CN', 'zh-HK', 'zh-TW', 'ja-JP', 'es-ES', 'fr-FR', 'fr-CA']
• and I added those line in ./lib/lang.js for French

  fr: {
    NAV: {
      INDEX: 'Blog',
      RSS: 'RSS',
      SEARCH: 'Chercher',
      ABOUT: 'À propos'
    },
    PAGINATION: {
      PREV: 'Précédent',
      NEXT: 'Suivant'
    },
    POST: {
      BACK: 'Retour',
      TOP: 'Haut'
    }
  }

…

    case 'fr':
    case 'fr-CA':
    case 'fr-FR':
      return lang.fr

[JOduMonT]

as @craigary mentioned; in lib/lang.js language and country code have to be in lowercase (fr-fr, fr-ca, en-ca, en-uk, …) but in blog.config.js it is fine to write the country in UPPERCASE (lang: ‘fr-CA’)

[craigary]

I guess you might need to use lower case instead, btw can you help me to fix case 'es-ES' to 'es-es' please 😃