html[lang]: use `site.Language.Lang` when `languageCode` is not set.

Regis Philibert

03.53.2023 906d7bec021a01076abfb9de4109495b02356f55

1
2
{{ $new_window_icon_size := "8px" }}
<span class="new-window">{{ partial "svg/new-window.svg" (dict "size" $new_window_icon_size) }}</span>