feat: add danmuku plugin and i18n setup documentation

- Created a new documentation file for the danmuku plugin with code examples.
- Added a new documentation file for language settings (i18n) with detailed instructions on language imports, default languages, and how to add or modify languages.

docs/assets/ts/artplayer-proxy-mediabunny.d.ts

@@ -75,5 +75,5 @@ declare const artplayerProxyMediabunny: (option?: Option) => (art: Artplayer) =>
 
 export default artplayerProxyMediabunny
 
-export = artplayerProxyMediabunny
-export as namespace artplayerProxyMediabunny;
+export = artplayerProxyMediabunny;
+export as namespace artplayerProxyMediabunny;