add post build script

This is to restore the patch of emotion: emotion-js/emotion#2651, because rollup will concat these two strings to one.

package.json

@@ -11,6 +11,7 @@
     "dev": "vite",
     "prepublish": "npm run typings && npm run build",
     "build": "vite build",
+    "postbuild": "sed -i -e 's/\"useInsertionEffect\"/\"useInsertion\"+\"Effect\"/g' ./dist/index.es.js",
     "typings": "tsc --emitDeclarationOnly",
     "preview": "vite preview"
   },