feat: importer starting point

package.json

@@ -34,6 +34,7 @@
     "@types/node": "^25.2.3",
     "@types/react": "^19.2.14",
     "@types/react-dom": "^19.2.3",
+    "@types/turndown": "^5.0.6",
     "@vitejs/plugin-react": "^5.1.4",
     "@vitest/coverage-v8": "^4.0.18",
     "@vitest/ui": "^4.0.18",
@@ -66,6 +67,7 @@
     "@milkdown/react": "^7.18.0",
     "@milkdown/theme-nord": "^7.18.0",
     "@monaco-editor/react": "^4.7.0",
+    "@xmldom/xmldom": "^0.8.11",
     "chokidar": "^5.0.0",
     "date-fns": "^4.1.0",
     "drizzle-orm": "^0.45.1",
@@ -78,6 +80,7 @@
     "react-hot-toast": "^2.6.0",
     "sharp": "^0.34.5",
     "snowball-stemmers": "^0.6.0",
+    "turndown": "^7.2.2",
     "zod": "^4.3.6",
     "zustand": "^5.0.11"
   },