convert = function(s, numRows) {
  let data = {
      col: 0,
      row: 0,
      index: 0,
      table: [],
      word: s,
      numRows
  }

  while (data.index < s.length) {
      data = goDown(data);
      data = goDiagonal(data);
  }

  console.table(data.table);
  return data.table.map(row => row.join('')).join('');
}
@param {string} s
@param {number} numRows
@return {string}