chore: fix npm start in window (#39252)

* Feat: Added instructions for the win environment~

* feat: Use cross-env to set the environment variables

package.json

@@ -86,7 +86,7 @@
     "site": "dumi build && cp .surgeignore _site",
     "sort": "npx sort-package-json",
     "sort-api": "antd-tools run sort-api-table",
-    "start": "PORT=8001 dumi dev",
+    "start": "cross-env PORT=8001 dumi dev",
     "test": "jest --config .jest.js --cache=false",
     "test:update": "jest --config .jest.js --cache=false -u",
     "test-all": "sh -e ./scripts/test-all.sh",