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.

docs/assets/ts/artplayer-plugin-ads.d.ts

@@ -1,8 +1,3 @@
-import type Artplayer from 'artplayer'
-
-export = artplayerPluginAds
-export as namespace artplayerPluginAds;
-
 interface Option {
   /**
    * 广告源文本，支持视频链接、图片链接、HTML文本
@@ -50,3 +45,8 @@ interface Ads {
 }
 
 declare const artplayerPluginAds: (option: Option) => (art: Artplayer) => Ads
+
+export default artplayerPluginAds
+
+export = artplayerPluginAds;
+export as namespace artplayerPluginAds;