Update README.md

		
		Customization is allowed as like below
		
		1. DropDownList source inherits UITableViewSource, so any developer can customize the source and modify the look and feel as they like
		2. Any developer can modify the Handle Image by using the code dropdownlist. Usage:dropDownList.HandleImage = UIImage.FromBundle ("your image file path");
		3. Direction of the drop down can be set to up or down Usage: dropDownList.DropDownDirection = DropDownDirectionValue.Down;
		4. Size of DropDownList can be set via constructor or empty constructor default to 0,0, 200,75
		5. Total visible rows in the drop down can be controlled using VisibleRows property. Usage: dropDownList.VisibleRows = 10;