implement i18next and add some example translations including german

[flx-sta]

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Summary

It adds a general internationalisation (i18n) implementation that can be extended to the whole application. For now I've only translated a bit (english and german) for presentational purposes

Screenshots

Test Plan

If you want to check the application in german you either have to set your device to german or open the branch in your IDE and in i18n.ts add the lng property with "de" as value:

i18n
  .use(languageDetector)
  .use(initReactI18next)
  .init({
    resources: {
      en: {
        translation: english,
      },
      de: {
        translation: german,
      },
    },
    fallbackLng: "en",
    lng: "de",                      // <--------------------
    interpolation: {
      escapeValue: false, // react already safes from xss => https://www.i18next.com/translation-function/interpolation#unescape
    },
    compatibilityJSON: "v3",
  });

fixes #586

[ann0see]

Great! I also thought about requesting that. Thanks!

In our project (jamulus.io) we use a web app for easier translation by the community. We use Hosted Weblate but I think there are others too.

[flx-sta]

@ann0see yeah I could see that in the future as i18next has support for that but 1 thing after another 😁

https://react.i18next.com/guides/multiple-translation-files#manage-your-translations-with-a-management-gui

[gkasdorf]

This is great. Holding off on merging as you requested.

[gkasdorf]

@Felix-Staud Let me know whenever you think this is good to go. I tested it and it seems great!

[flx-sta]

@gkasdorf It's now ready to be merged.
Unfortunately a full fledged review will take forever but isn't that what a beta testing is for ? 👀