Paired locales as nodes in API response, when querying for documents with localization enabled

[quornik]

Feature idea & request: An ability to determine if the document I'm fetching, has it's corresponding siblings in other locales.

This way, while doing the language switch on frontend, it would be much easier to create link the switch is pointing to. If for example, page we are currently on doesn't have its siblings, lang switch should point user to homepage (in example). IF it does have one, switching language should point user to the corresponding document.

in nextjs, language switch can look similar to this:

{locales
  .filter((loc) => loc != locale)
  .map((loc, idx) => (
    <Link
      key={`linkloc-${idx}`}
     locale={locale == 'pl' ? 'en' : 'pl'} //exemple href: /en/portfolio/project-name
      href={router.asPath}
      
    >
      <a>
        {loc}
      </a>
    </Link>
  ))}

In case above, everything works fine if every page has its matching sibling. If not, 404. To avoid that, we should have simple way to determine if the article has its multilingual siblings.

In some other CMS solutions with localization options, it is often a good practice that document request returns a field (or fields) with the information of localization status.