chore: add optional prepare script

Author: pr-Mais

extensions/firestore-huggingface-inference-api/functions/package.json

@@ -1,6 +1,7 @@
 {
   "name": "functions",
   "scripts": {
+    "prepare": "npm run lerna:bootstrap && npm run lerna:link",
     "lint": "eslint \"src/**/*\"",
     "lint:fix": "eslint \"src/**/*\" --fix",
     "build": "tsc",
@@ -27,4 +28,4 @@
     "ts-jest": "^29.1.0"
   },
   "private": true
-}
+}