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/document/assets/start_i18n.md.B0XPxv4h.lean.js

@@ -0,0 +1 @@
+import{_ as a,o as i,c as n,ak as l}from"./chunks/framework.xxfEszSJ.js";const c=JSON.parse('{"title":"语言设置","description":"","frontmatter":{},"headers":[],"relativePath":"start/i18n.md","filePath":"start/i18n.md","lastUpdated":1757137705000}'),p={name:"start/i18n.md"};function e(h,s,t,k,r,E){return i(),n("div",null,s[0]||(s[0]=[l("",14)]))}const g=a(p,[["render",e]]);export{c as __pageData,g as default};