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/FooterVersion.tsx

@@ -0,0 +1,28 @@
+import { useMemo } from 'react'
+
+interface FooterVersionProps {
+  version: string
+}
+
+export const FooterVersion = (props: FooterVersionProps): JSX.Element => {
+  const { version } = props
+
+  const versionLink = useMemo(() => {
+    return `https://github.com/theoludwig/theoludwig/releases/tag/v${version}`
+  }, [version])
+
+  return (
+    <p className='mt-1'>
+      Version{' '}
+      <a
+        data-cy='version-link'
+        className='text-yellow hover:underline dark:text-yellow-dark'
+        href={versionLink}
+        target='_blank'
+        rel='noopener noreferrer'
+      >
+        {version}
+      </a>
+    </p>
+  )
+}