feat: add environment variable configuration template

- Add .env.example with documented environment variables
- Provides clear template for local development setup
- Follows Next.js configuration best practices

Author: ken-guru

.env.example

@@ -0,0 +1,19 @@
+# Example environment variables
+# Copy this file to .env.local and update with your values
+
+# App Configuration
+NEXT_PUBLIC_APP_NAME=Mr. Timely
+NEXT_PUBLIC_BASE_URL=https://your-domain.com
+
+# Analytics (optional)
+# NEXT_PUBLIC_GA_ID=G-XXXXXXXXXX
+
+# Database (if using)
+# DATABASE_URL=your-database-url
+
+# Third-party services (if using)
+# STRIPE_PUBLISHABLE_KEY=pk_test_
+# STRIPE_SECRET_KEY=sk_test_
+
+# Development only
+# NEXT_PUBLIC_DEBUG=true