Added #

• Initial release of customizable_download_button package
• DownloadController abstract class for download management
• RealDownloadController implementation with HTTP streaming
• CustomizableDownloadButton widget with extensive customization options
• DownloadButtonConfig class with 30+ customization properties
• DownloadService utility class for file operations
• DownloadStatus enum for tracking download states
• Four built-in style presets: Material, Cupertino, Minimal, and Rounded
• Support for custom colors, text, icons, shapes, and animations
• Pause/cancel download functionality
• Open downloaded files with system default application
• Smooth animations and transitions between states
• Complete documentation and examples with 8 different styles