xhtml link element feature for multi language site

[Aadi-aditya-11]

it will help alot to many users who have multi language sitemap as they had to customise so solve this.
example :

<url xmlns:xhtml="http://www.w3.org/1999/xhtml">
    <loc>https://www.example.com/en/slug</loc>
    <xhtml:link rel="alternate" hreflang="en" href="https://www.example.com/en/slug" />
    <xhtml:link rel="alternate" hreflang="hi" href="https://www.example.com/hi/slug" />
</url>