combineCharacter
Given inputs of an choseong, jungseong, and jongseong return a single Korean character
function combineCharacter(choseong: string, jungseong: string, jongseong?: string): string;Examples
combineCharacter('ㄱ', 'ㅏ', 'ㅂㅅ'); // '값'
combineCharacter('ㅌ', 'ㅗ'); // '토'