feat: 添加 Markdown 预览组件和相关样式，更新编辑器功能

package.json

@@ -33,13 +33,17 @@
     "@tiptap/starter-kit": "^3.13.0",
     "@tiptap/suggestion": "^3.13.0",
     "dayjs": "^1.11.19",
+    "github-markdown-css": "^5.8.1",
     "highlight.js": "^11.11.1",
     "lit-html": "^3.3.1",
     "lowlight": "^3.3.0",
+    "marked": "^17.0.1",
+    "marked-highlight": "^2.2.3",
     "nanoid": "^5.1.6",
     "react": "^19.2.1",
     "react-dom": "^19.2.1",
     "tiptap-markdown": "^0.9.0",
+    "turndown": "^7.2.2",
     "zustand": "^5.0.9"
   },
   "devDependencies": {
@@ -61,7 +65,6 @@
   "exports": {
     ".": "./dist/kv-md.js",
     "./kv-md.js": "./dist/kv-md.js",
-    "./kv-md.css": "./dist/kv-md.css",
-    "./mod.ts": "./mod.ts"
+    "./kv-md.css": "./dist/kv-md.css"
   }
 }