Added script for starting with env variables.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "umami",
-  "version": "0.66.0",
+  "version": "0.67.0",
   "description": "A simple, fast, website analytics alternative to Google Analytics. ",
   "author": "Mike Cao <mike@mikecao.com>",
   "license": "MIT",
@@ -13,6 +13,7 @@
     "dev": "next dev",
     "build": "npm-run-all build-tracker build-lang build-geo build-db build-app",
     "start": "next start",
+    "start-env": "node scripts/start-env.js",
     "build-app": "next build",
     "build-tracker": "rollup -c rollup.tracker.config.js",
     "build-db": "npm-run-all copy-db-schema build-db-client",