feat: add danmuku plugin documentation and i18n setup guide

- Created a new documentation file for the danmuku plugin, detailing its usage and providing code examples.
- Added a comprehensive guide for language settings (i18n), including instructions for importing languages, setting default languages, and modifying language options.
- Included code snippets for initializing the Artplayer with different languages and examples for adding new languages.

docs/document/assets/en_start_i18n.md.yt4abE_S.lean.js

@@ -0,0 +1 @@
+import{_ as a,c as i,o as n,ak as l}from"./chunks/framework.CIzAx-5p.js";const g=JSON.parse('{"title":"Language Settings","description":"","frontmatter":{},"headers":[],"relativePath":"en/start/i18n.md","filePath":"en/start/i18n.md","lastUpdated":1745114138000}'),e={name:"en/start/i18n.md"};function p(t,s,h,r,k,E){return n(),i("div",null,s[0]||(s[0]=[l("",13)]))}const c=a(e,[["render",p]]);export{g as __pageData,c as default};