feat: add Arabic language support to documentation and type definitions

packages/artplayer-vitepress/docs/start/i18n.md

@@ -30,7 +30,7 @@ var art = new Artplayer({
 
 打包后的语言文件存放于: `artplayer/dist/i18n/*.js`
 
-手动导入的语言有: `cs`, `es`, `fa`, `fr`, `id`, `pl`, `ru`, `zh-tw`
+手动导入的语言有: `cs`, `es`, `fa`, `fr`, `id`, `pl`, `ru`, `ar`, `zh-tw`
 
 ::: code-group