Add an npm script

Author: wooorm

package.json

@@ -58,6 +58,7 @@
     "xo": "^0.53.0"
   },
   "scripts": {
+    "prepack": "npm run build && npm run format",
     "build": "tsc --build --clean && tsc --build && type-coverage",
     "format": "remark . -qfo && prettier . -w --loglevel warn && xo --fix",
     "test-api": "node --conditions development test.js",