feat: rewrite to Next.js v13 app directory

Improvements:
- Hide switch theme input (ugly little white square)
- i18n without subpath (e.g: /fr or /en), same url whatever the locale used

components/Footer/FooterText.tsx

@@ -0,0 +1,19 @@
+import Link from 'next/link'
+
+import { getI18n } from '@/i18n/i18n.server'
+
+export const FooterText = (): JSX.Element => {
+  const i18n = getI18n()
+
+  return (
+    <p>
+      <Link
+        href='/'
+        className='text-yellow hover:underline dark:text-yellow-dark'
+      >
+        Théo LUDWIG
+      </Link>{' '}
+      | {i18n.translate('common.all-rights-reserved')}
+    </p>
+  )
+}