✨ Add animation lifecycle callbacks

[almond-bongbong]

Add Animation Lifecycle Callbacks

Overview

This PR introduces animation lifecycle callback props to the SlotCounter component, allowing users to track the start and end of animations.

Changes

• Add onAnimationStart and onAnimationEnd callback props
• Implement animation state tracking using isAnimatingRef
• Add transition end event listener to handle animation completion
• Handle edge cases when new animation starts while previous one is still running
• Use ref pattern to prevent unnecessary re-renders from callback changes

Implementation Details

• Used useRef to store callback functions to prevent unnecessary re-renders
• Added transitionend event listener to detect animation completion
• Properly cleanup event listeners to prevent memory leaks
• Handle edge cases where new animation starts before previous one completes

Usage Example

<SlotCounter
  value={value}
  onAnimationStart={() => console.log('Animation started')}
  onAnimationEnd={() => console.log('Animation completed')}
/>

[almond-bongbong]

Please add a quick note in the README about onAnimationStart and onAnimationEnd. Thanks.