docs(readme): add v2 documentation (#65)

- Migration Guide: v1 to v2
- v1 Legacy Version
- update v1 to v2 guide

Author: saseungmin

.changeset/funny-moons-hear.md

@@ -7,19 +7,127 @@
 
 feat!: introduce hooks-based API for v2.0
 
-BREAKING CHANGE: Complete API redesign with React hooks
+> [!important]
+> BREAKING CHANGE: **Complete API Redesign with React Hooks**
 
-- Replace `YoutubePlayer` component with `YoutubeView` + `useYouTubePlayer` hook
-- Add `useYouTubeEvent` hook for reactive event handling
-- Remove ref-based imperative API in favor of declarative approach
-- Simplify component props and reduce coupling between components
-- Follow expo patterns for better DX
+#### New Hooks-Based Architecture
 
-Migration required from v1:
+- **`useYouTubePlayer(videoId, config)`** - Creates a player instance with declarative configuration
+- **`useYouTubeEvent(player, eventName, intervalOrDefault?, deps?)`** - Reactive event handling with complete type inference
+- **`YoutubeView`** - Simplified view component that accepts a player instance
 
-- `YoutubePlayer` → `YoutubeView` + `useYouTubePlayer()`
-- Event props → `useYouTubeEvent()` hooks
-- `playerRef.current.method()` → `player.method()`
+#### Migration from v1 to v2
 
-Fixes: Memory leaks, complex state management, tight coupling
-Improves: Developer experience, maintainability, performance
+**Before (v1):**
+```jsx
+// Imperative, ref-based API
+const playerRef = useRef<PlayerControls>(null);
+
+<YoutubePlayer
+  ref={playerRef}
+  source={videoId}
+  onReady={handleReady}
+  onStateChange={handleStateChange}
+  onProgress={handleProgress}
+  playerVars={{ autoplay: true }}
+/>
+
+// Manual event handlers and state management
+const [isPlaying, setIsPlaying] = useState(false);
+const handleStateChange = (state) => setIsPlaying(state === PlayerState.PLAYING);
+```
+
+**After (v2):**
+```jsx
+// Declarative, hooks-based API
+const player = useYouTubePlayer(videoId, {
+  autoplay: true,
+  controls: true,
+  playsinline: true
+});
+
+<YoutubeView player={player} />
+
+// Reactive state with automatic updates - two usage patterns:
+
+// 1. State-based (returns reactive values)
+const playbackRate = useYouTubeEvent(player, 'playbackRateChange', 1);
+const progress = useYouTubeEvent(player, 'progress', 1000); // 1000ms interval
+const state = useYouTubeEvent(player, 'stateChange');
+
+const isPlaying = state === PlayerState.PLAYING;
+
+// 2. Callback-based (for side effects)
+useYouTubeEvent(player, 'ready', (playerInfo) => {
+  console.log('Player ready:', playerInfo);
+});
+
+useYouTubeEvent(player, 'error', (error) => {
+  console.error('Player error:', error);
+});
+```
+
+### ✨ New Features
+
+- **Declarative Configuration**: Configure player options directly in `useYouTubePlayer` hook
+- **Automatic State Management**: No need to manually manage state for common use cases
+- **Reactive Events**: `useYouTubeEvent` with two usage patterns - state-based for reactive values and callback-based for side effects
+- **Better TypeScript Support**: Improved type inference and autocomplete
+- **Reduced Boilerplate**: Significantly less code required for common operations
+- **Automatic Cleanup**: Hooks handle cleanup automatically, preventing memory leaks
+
+### 🎯 Improvements
+
+- **Reduced Coupling**: Eliminated ref dependencies between parent and child components
+- **Simplified API**: Fewer props to manage, more intuitive usage patterns
+- **Better Developer Experience**: Following established React Native patterns (expo-audio, expo-video)
+- **Performance**: More efficient event handling with automatic cleanup
+- **Maintainability**: Cleaner separation of concerns
+
+### 📦 Component Changes
+
+#### Removed
+- ❌ `YoutubePlayer` component (replaced by `YoutubeView`)
+- ❌ `PlayerControls` ref interface
+- ❌ Direct event props (`onReady`, `onStateChange`, `onProgress`, etc.)
+
+#### Added
+- ✅ `YoutubeView` component
+- ✅ `useYouTubePlayer` hook
+- ✅ `useYouTubeEvent` hook
+- ✅ Simplified prop interface
+
+### 📚 Migration Guide
+
+For detailed migration examples and step-by-step instructions, see our [Migration Guide](/packages/react-native-youtube-bridge/docs/migration-v2.md).
+
+Key migration steps:
+1. **Replace `YoutubePlayer` with `YoutubeView` + `useYouTubePlayer`**
+2. **Convert event props to `useYouTubeEvent` hooks** (state-based or callback-based)
+3. **Move `playerVars` to `useYouTubePlayer` config**
+4. **Replace ref-based method calls with direct player method calls**
+5. **Remove manual state management for events**
+
+### ⚠️ Breaking Changes
+
+- **API Surface**: Complete API redesign, no backward compatibility
+- **Event Handling**: Manual event listeners replaced with reactive hooks
+- **Component Structure**: `YoutubePlayer` split into `YoutubeView` + hooks
+
+### 🐛 Bug Fixes
+- Fixed memory leaks from improper event cleanup
+- Better handling of rapid video ID changes
+- Manage multiple players independently
+
+### 📖 Documentation
+- Complete API documentation rewrite
+- Added migration guide from v1
+- Updated all examples to use v2 API
+- Added TypeScript usage examples
+
+---
+
+## Previous Versions
+
+### [1.x.x] - Legacy Version
+See [v1 documentation](/packages/react-native-youtube-bridge/docs/v1.md) for the previous imperative API.