code: func (buttons *Buttons) Markup(columns int) Keyboard {
  	keyboard := Keyboard{}
  
  	col := 0
  
  	row := Buttons{}
  	len := len(*buttons)
  	for i, button := range *buttons {
  		row.Append(button.Data, button.Text)
  		col++
  		if col == columns || i == (len-1) {
  			col = 0
  			keyboard.AddRows(row)
  			row = Buttons{}
  		}
  	}
  
  	return keyboard
  }
docs: // Markup generate Keyboard from Buttons ([]Button), chunking buttons by columns number