Hugo does support country-specific language codes.
Yet, the languageCode
seems to set the language without a ‘sub-regional’ context only.
(The issue you are pointing to is theme-specific and can easily be solved, I guess.)
You can use the following:
languageCode: de-at
For a multilingual website you can use this:
defaultContentLanguage: de
languages:
de:
weight: 1
languageCode: de-at
en:
…
In your baseof.html
you can use this:
<html lang="{{ .Site.LanguageCode }}">
If you go to http://localhost:1313/index.xml
you will also find this line:
<language>de-at</language>