refactor: update export syntax to default for multiple plugins and adjust package.json formatting

packages/artplayer-proxy-canvas/types/artplayer-proxy-canvas.d.ts

@@ -1,10 +1,9 @@
 import type Artplayer from 'artplayer'
 
-export = artplayerProxyCanvas
-export as namespace artplayerProxyCanvas;
-
 type Option = (ctx: CanvasRenderingContext2D, video: HTMLVideoElement) => void
 
 type Result = HTMLCanvasElement
 
 declare const artplayerProxyCanvas: (option: Option) => (art: Artplayer) => Result
+
+export default artplayerProxyCanvas