Takes any vector of countries and returns languages.
Examples
lang.country('AD')
#> $AD
#> [1] "Catalan" "Occitan" "Spanish" "Portuguese" "French"
#>
lang.country(c('AD', 'AE'))
#> $AD
#> [1] "Catalan" "Occitan" "Spanish" "Portuguese" "French"
#>
#> $AE
#> [1] "Soqotri" "Standard Arabic" "Omani Arabic" "Najdi Arabic"
#> [5] "Gulf Arabic" "Ru'us al-Jibal"
#>