Render alternate urls for localized entries

[daun]

Render link tags for localized entries. Uses the full locale (en-UK, not en).

<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"
  xmlns:xhtml="http://www.w3.org/1999/xhtml">
  <url>
    <loc>https://www.example.com/english/page.html</loc>
    <xhtml:link
               rel="alternate"
               hreflang="de-DE"
               href="https://www.example.de/deutsch/page.html"/>
    <xhtml:link
               rel="alternate"
               hreflang="en-UK"
               href="https://www.example.com/english/page.html"/>
  </url>
</urlset>

[martyf]

Thanks for this - have tagged with 3.5.0