Added the foundation for making the frontend multilingual. Now only need to import useTranslation and use t('key') for all user-facing text for all pages (+add key:value pairs in src/locales for each language ofc)

- package.json -> Imported packages i18next & react-i18next for multilingual functionality.
- src/App.jsx -> Imported LanguageSwitcher from ./components/LanguageSwitcher and added <LanguageSwitcher /> component at the beginning of layout so it's always visible.
- src/components/LanguageSwitcher.jsx -> LanguageSwitcher component, consists of a dropdown menu that always appears at top right corner for choosing language.
- src/i18n.js -> Initialize and configure i18next for app-wide multilingual support.
- src/locales/en.json + src/locales/fr.json -> Empty json files that will soon contain translation key:value pairs for each page.
- src/main.jsx -> Imported src/i18n.js for multilingual functionality.

Frontend/src/i18n.js

@@ -0,0 +1,26 @@
+import i18n from 'i18next';
+import { initReactI18next } from 'react-i18next';
+
+import en from './locales/en.json';
+import fr from './locales/fr.json';
+// import more languages as needed
+
+const resources = {
+  en: { translation: en },
+  fr: { translation: fr },
+  // add other languages here
+};
+
+i18n
+  .use(initReactI18next)
+  .init({
+    resources,
+    lng: 'en', // default language
+    fallbackLng: 'en',
+    //interpolation: {
+    //  escapeValue: false, // not needed for React
+    //},
+  });
+
+export default i18n;
+