docs: def format_sentence(sentence):
      ''' fix display formatting of a sentence array '''
      for index, word in enumerate(sentence):
          if word == 'a' and index + 1 < len(sentence) and \
                  re.match(r'^[aeiou]', sentence[index + 1]) and not \
                  re.match(r'^uni', sentence[index + 1]):
              sentence[index] = 'an'
      text = ' '.join(sentence)
      text = '%s%s' % (text[0].upper(), text[1:])
      text = text.replace(' ,', ',')
      return '%s.' % text