feat: add danmuku plugin documentation and i18n setup guide

- Created a new documentation file for the danmuku plugin with code examples.
- Added comprehensive i18n setup instructions, including default language settings, language imports, and examples for adding and modifying languages.
- Updated the structure and content of the i18n documentation to enhance clarity and usability.

scripts/plugin/template/package.json

@@ -20,7 +20,13 @@
   "exports": {
     ".": {
       "import": "./dist/artplayer-plugin-{{name}}.mjs",
-      "require": "./dist/artplayer-plugin-{{name}}.js"
+      "require": "./dist/artplayer-plugin-{{name}}.js",
+      "types": "./types/artplayer-plugin-{{name}}.d.ts"
+    },
+    "./legacy": {
+      "import": "./dist/artplayer-plugin-{{name}}.legacy.js",
+      "require": "./dist/artplayer-plugin-{{name}}.legacy.js",
+      "types": "./types/artplayer-plugin-{{name}}.d.ts"
     }
   },
   "main": "dist/artplayer-plugin-{{name}}.js",