Introduce i18n

src/pages/_app.tsx

@@ -1,4 +1,5 @@
 import type { AppProps } from 'next/app'
+import { appWithTranslation } from 'next-i18next'
 import { ThemeProvider } from 'theme-ui'
 import { theme } from '../lib/theme'
 
@@ -10,4 +11,4 @@ function MyApp({ Component, pageProps }: AppProps) {
   )
 }
 
-export default MyApp
+export default appWithTranslation(MyApp)