fix(types): correct notice.show getter return type (#1055)

The notice.show getter was declared as boolean while the setter accepts string, Error or false. TypeScript uses the getter return type when checking property assignment, causing TS2322 when assigning a string to notice.show.

packages/artplayer/types/artplayer.d.ts

@@ -152,7 +152,7 @@ export default class Artplayer extends Player {
 
   readonly notice: {
     timer: number | null
-    get show(): boolean
+    get show(): string | Error | false | ''
     set show(msg: string | Error | false | '')
     destroy: () => void
   }