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/en_index.md.CYpcDsY6.lean.js

@@ -0,0 +1 @@
+import{_ as i,o as a,c as n,ak as l}from"./chunks/framework.xxfEszSJ.js";const g=JSON.parse('{"title":"Installation & Usage","description":"","frontmatter":{},"headers":[],"relativePath":"en/index.md","filePath":"en/index.md","lastUpdated":1767420511000}'),p={name:"en/index.md"};function t(e,s,h,k,r,E){return a(),n("div",null,s[0]||(s[0]=[l("",50)]))}const c=i(p,[["render",t]]);export{g as __pageData,c as default};