feat: add artplayer-plugin-audio-track for audio synchronization with video

- Implemented the audio track plugin for ArtPlayer, allowing audio to be synchronized with video playback.
- Added main functionality in `src/index.js` to handle audio playback, synchronization, and event listeners for play, pause, seek, and volume changes.
- Created TypeScript definitions for the plugin in `types/artplayer-plugin-audio-track.d.ts`.
- Included necessary build files in `dist/` for various module formats (CommonJS, ES Module, and legacy).
- Updated package metadata in `package.json` and added a README for documentation.
- Added `.npmignore` to exclude unnecessary files from the package.

packages/artplayer-plugin-audio-track/src/index.js

@@ -0,0 +1,76 @@
+export default function artplayerPluginAudioTrack(option) {
+  return (art) => {
+    const { url, offset = 0, sync = 0.3 } = option
+
+    if (!url) {
+      return {
+        name: 'artplayerPluginAudioTrack',
+      }
+    }
+
+    const audio = new Audio()
+    audio.src = url
+    audio.preload = 'auto'
+
+    function syncAudio() {
+      if (!art.video)
+        return
+
+      const videoTime = art.currentTime
+      const targetTime = videoTime + offset
+
+      if (Math.abs(audio.currentTime - targetTime) > sync) {
+        audio.currentTime = targetTime
+      }
+    }
+
+    art.on('play', () => {
+      syncAudio()
+      audio.play().catch((err) => {
+        console.warn(err)
+      })
+    })
+
+    art.on('pause', () => {
+      audio.pause()
+    })
+
+    art.on('seek', () => {
+      syncAudio()
+    })
+
+    art.on('video:timeupdate', () => {
+      if (art.playing) {
+        syncAudio()
+      }
+    })
+
+    art.on('video:ratechange', () => {
+      audio.playbackRate = art.video.playbackRate
+    })
+
+    art.on('video:volumechange', () => {
+      audio.volume = art.volume
+      audio.muted = art.muted
+    })
+
+    art.on('destroy', () => {
+      audio.pause()
+      audio.src = ''
+      audio.load()
+    })
+
+    audio.volume = art.volume
+    audio.muted = art.muted
+    audio.playbackRate = art.video?.playbackRate || 1
+
+    return {
+      name: 'artplayerPluginAudioTrack',
+      audio,
+    }
+  }
+}
+
+if (typeof window !== 'undefined') {
+  window.artplayerPluginAudioTrack = artplayerPluginAudioTrack
+}