fix(env): added NEXT_PUBLIC_APP_URL to .env.example (#485)

Author: waleedlatif1

apps/sim/.env.example

@@ -5,7 +5,10 @@ DATABASE_URL="postgresql://postgres:password@localhost:5432/postgres"
 BETTER_AUTH_SECRET=your_secret_key  # Use `openssl rand -hex 32` to generate, or visit https://www.better-auth.com/docs/installation
 BETTER_AUTH_URL=http://localhost:3000
 
-## Security (Required)
+# NextJS (Required)
+NEXT_PUBLIC_APP_URL=http://localhost:3000
+
+# Security (Required)
 ENCRYPTION_KEY=your_encryption_key  # Use `openssl rand -hex 32` to generate
 
 # Email Provider (Optional)