adding prepare script

Author: jdaigneau5

package.json

@@ -42,7 +42,8 @@
     "test:downstream": "NODE_CONFIG_ENV=devel npm --prefix ../cve-pkg-tester run test",
     "prettier": "prettier --config .prettierrc --write .",
     "prep:publish": "npm pack --dry-run",
-    "coverage": "jest --coverage"
+    "coverage": "jest --coverage",
+    "prepare": "npm run build:all"
   },
   "license": "(CC0)",
   "dependencies": {