added postinstall and removed other generate-env from package.json

package.json

@@ -4,25 +4,8 @@
   "license": "Apache-2.0",
   "sideEffects": false,
   "scripts": {
-    "generate-env": "node scripts/generateEnv.js",
-    "prebuild": "pnpm run generate-env",
-    "prebuild:clean": "pnpm run generate-env",
-    "predev": "pnpm run generate-env",
-    "pretest": "pnpm run generate-env",
-    "prelint": "pnpm run generate-env",
-    "prelint:fix": "pnpm run generate-env",
-    "preformat": "pnpm run generate-env",
-    "pretypecheck": "pnpm run generate-env",
-    "prechangeset:publish": "pnpm run generate-env",
-    "predev:react": "pnpm run generate-env",
-    "preserve:react": "pnpm run generate-env",
-    "prebuild:react": "pnpm run generate-env",
-    "predev:react-boilerplate": "pnpm run generate-env",
-    "preserve:react-boilerplate": "pnpm run generate-env",
-    "prebuild:react-boilerplate": "pnpm run generate-env",
-    "predev:next": "pnpm run generate-env",
-    "preserve:next": "pnpm run generate-env",
-    "prebuild:next": "pnpm run generate-env",
+    "generate-env": "(cp .env.example .env) || echo .env already exists && node scripts/generateEnv.js",
+    "postinstall": "pnpm generate-env",
     "build": "turbo run build --filter={packages/*}",
     "build:clean": "turbo run build:clean",
     "dev": "turbo run dev --filter={packages/*}",