code: function isRomaji(input = '') {
    if (isEmpty(input)) return false;
    return [...input].every((char) => isCharRomaji(char));
  }
docs: Test if `input` is [Romaji](https://en.wikipedia.org/wiki/Romaji) (allowing [Hepburn romanisation](https://en.wikipedia.org/wiki/Hepburn_romanization))
  @param  {String} [input=''] text
  @return {Boolean} true if [Romaji](https://en.wikipedia.org/wiki/Romaji)
  @example
  isRomaji('Tōkyō and Ōsaka')
  // => true
  isRomaji('a*b&c-d')
  // => true
  isRomaji('あアA')
  // => false
  isRomaji('お願い')
  // => false
  isRomaji('a！b&cーd') // Full-width punctuation fails
  // => false