code: function handleStrs(strs, opts) {
    const len = longest(strs)
    const text = strs
      .map(pad(len, opts.justify))
      .map(wrap(opts))
      .join('')
    return {len, text}
  }
docs: Builds middle of billboard from an array of strings.
  
  @param {String[]} strs - text to put on billboard
  @param {Object} opts - options for this billboard
  @returns {String} formatted string for middle of billboard