Numbers from 13 to 19 aren't pronounced correctly in English

[waelhasan]

When entering numbers from 13 to 19 it is handled the same as 'twenty' and 'thirty' ... etc, when it should be handled in 'Xteen' notation.

Examples

console.log(convert(13, { language: 'en'})) // ten three
console.log(convert(14, { language: 'en'})) // ten four
console.log(convert(15, { language: 'en'})) // ten five
console.log(convert(16, { language: 'en'})) // ten six
console.log(convert(17, { language: 'en'})) // ten seven
console.log(convert(18, { language: 'en'})) // ten eight
console.log(convert(19, { language: 'en'})) // ten nine