[Feature]: Add Storefront and Digital Product Delivery Integration Guide

[TheCyperpunk]

Description

This PR adds a comprehensive guide for setting up and using the Storefront and Digital Product Delivery features together in Dodo Payments.

What's Added

• New Guide: guides/storefront-digital-delivery-guide.mdx
• Navigation Update: Added guide to the "Guides" tab under a new "Setup Guides" group in docs.json

Guide Contents

The guide provides step-by-step instructions for:

• Creating digital products with automatic file delivery
• Setting up a branded storefront to showcase products
• Testing the complete purchase and delivery flow
• Understanding the customer experience
• Advanced configuration (bundles, subscriptions, custom URLs)
• Best practices for security, file management, and customer experience
• Troubleshooting common issues

Features Covered

• ✅ Digital Product Delivery (file uploads and external links)
• ✅ Storefront setup and branding
• ✅ Product publishing and management
• ✅ Test mode vs Live mode
• ✅ Customer portal access
• ✅ Email delivery automation

Related Issues

Closes #[issue-number] - Guide for Storefront and Digital Product Delivery

Checklist

• Guide follows existing documentation structure and style
• All internal links reference existing documentation pages
• Navigation properly updated in docs.json
• Content is clear, comprehensive, and beginner-friendly
• Includes troubleshooting section
• References existing images from the documentation

Testing

Tested locally with mintlify dev to ensure:

• Guide renders correctly
• Navigation links work properly
• All formatting displays as expected
• Images load correctly

Hacktoberfest

This contribution is part of Hacktoberfest 2025 🎃

[TheCyperpunk]

feat: add storefront and digital product delivery guide

• Add comprehensive guide for setting up storefront with digital delivery
• Include step-by-step instructions for product creation and configuration
• Add troubleshooting section and best practices
• Update navigation in docs.json with new "Setup Guides" group
• Closes #[issue-number]