add a README to track missing but wanted languages
add a README to track missing but wanted languages

freedesktop-unofficial-mirror/libreoffice__libexttextcat,giuliopaci/libexttextcat,tripleee/libexttextcat,giuliopaci/libexttextcat,freedesktop-unofficial-mirror/libreoffice__libexttextcat,tripleee/libexttextcat,tripleee/libexttextcat,giuliopaci/libexttextcat,freedesktop-unofficial-mirror/libreoffice__libexttextcat