feat: add Arabic language support to documentation and type definitions

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

@@ -29,7 +29,7 @@ var art = new Artplayer({
 Language files before packaging are located in: `artplayer/src/i18n/*.js`. You are welcome to add your language.
 Packaged language files are located at: `artplayer/dist/i18n/*.js`
 
-Manually imported languages include: `cs`, `es`, `fa`, `fr`, `id`, `pl`, `ru`, `zh-tw`
+Manually imported languages include: `cs`, `es`, `fa`, `fr`, `id`, `pl`, `ru`, `ar`, `zh-tw`
 
 ::: code-group
 

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