feat: use en as i18n fallback (#41246)

* feat: use en as i18n fallback

Loads the English versions of the files as a "fallback" language
to avoid displaying keys when a translation is missing.

* fix: use en as fallback key

client/i18n/config.js

@@ -7,7 +7,7 @@ const { i18nextCodes } = require('../../config/i18n/all-langs');
 const i18nextCode = i18nextCodes[clientLocale];
 
 i18n.use(initReactI18next).init({
-  fallbackLng: i18nextCode,
+  fallbackLng: 'en',
   lng: i18nextCode,
   // we only load one language since each language will have it's own server
   resources: {
@@ -16,6 +16,12 @@ i18n.use(initReactI18next).init({
       trending: require(`./locales/${clientLocale}/trending.json`),
       intro: require(`./locales/${clientLocale}/intro.json`),
       metaTags: require(`./locales/${clientLocale}/meta-tags.json`)
+    },
+    en: {
+      translations: require('./locales/english/translations.json'),
+      trending: require('./locales/english/trending.json'),
+      intro: require('./locales/english/intro.json'),
+      metaTags: require('./locales/english/meta-tags.json')
     }
   },
   ns: ['translations', 'trending', 'intro', 'metaTags'],