docs: function billboard(strOrStrs, customOpts) {
    const opts = merge({}, defaults, customOpts)
    const mid = typeof strOrStrs === 'object'
      ? lib.handleStrs(strOrStrs, opts)
      : lib.handleStr(strOrStrs, opts)
    const fill = opts.border.horizontal.repeat(mid.len)
    return [
      lib.top(fill, opts)
      , mid.text
      , lib.bot(fill, opts)
    ].join('')
  }