Add Impressum link to footer in de (github#34656)

components/page-footer/SmallFooter.tsx

@@ -1,6 +1,6 @@
 import Link from 'next/link'
 import { useRouter } from 'next/router'
-import { MarkGithubIcon } from '@primer/octicons-react'
+import { MarkGithubIcon, LinkExternalIcon } from '@primer/octicons-react'
 import { useTranslation } from '../hooks/useTranslation'
 
 export const SmallFooter = () => {
@@ -10,6 +10,15 @@ export const SmallFooter = () => {
     <div className="container-xl px-3 mt-6 pb-8 px-md-6 position-relative d-flex flex-row-reverse flex-xl-row flex-wrap flex-xl-nowrap flex-justify-center flex-xl-justify-between f6 color-fg-muted">
       <ul className="list-style-none d-flex flex-wrap col-12 flex-justify-center flex-xl-justify-between mb-2 mb-xl-0">
         <li className="mr-3 mr-xl-0">&copy; {new Date().getFullYear()} GitHub, Inc.</li>
+        {/* In Germany, Austria, and Switzerland, the Impressum link is legally required. */}
+        {router.locale === 'de' && (
+          <li className="mr-3 mr-xl-0">
+            <a href="https://aka.ms/impressum_de" target="_blank">
+              Impressum
+            </a>
+            <LinkExternalIcon size={12} />
+          </li>
+        )}
         <li className="mr-3 mr-xl-0">
           <Link href={`/${router.locale}/site-policy/github-terms/github-terms-of-service`}>
             {t('terms')}