feat: add danmuku plugin documentation and i18n setup instructions

- Created a new documentation file for the danmuku plugin with code examples.
- Added comprehensive language settings documentation, including default languages, importing languages, adding new languages, and modifying existing languages.
- Updated the i18n setup examples to reflect the latest changes in language handling.

packages/artplayer/types/option.d.ts

@@ -308,5 +308,3 @@ export interface Option {
         Record<CustomType, (this: Artplayer, video: HTMLVideoElement, url: string, art: Artplayer) => any>
     >
 }
-
-export default Option