feat: add environment variables template

Author: christophernemala

.env.example

@@ -0,0 +1,27 @@
+# Node.js Configuration
+NODE_VERSION=18.18.0
+NODE_OPTIONS=--max-old-space-size=4096
+
+# Package Manager
+PNPM_VERSION=8.15.6
+ENABLE_EXPERIMENTAL_COREPACK=1
+
+# Astro Configuration
+ASTRO_TELEMETRY_DISABLED=1
+
+# Vercel Deployment (Required for CI/CD)
+# Get these from: https://vercel.com/account/tokens
+VERCEL_TOKEN=your_vercel_token_here
+VERCEL_ORG_ID=your_vercel_org_id_here
+VERCEL_PROJECT_ID=your_vercel_project_id_here
+
+# WebContainer API Configuration
+# Cross-Origin Isolation Headers (automatically configured)
+CROSS_ORIGIN_EMBEDDER_POLICY=require-corp
+CROSS_ORIGIN_OPENER_POLICY=same-origin
+
+# Development Mode
+TUTORIALKIT_DEV=false
+
+# Production Optimizations
+NODE_ENV=production