Add --quickstart flag to init command

[gfscott]

Why are these changes introduced?

We want to make it fast to set up a Hydrogen app with a set of sensible defaults. This is helpful for users who are just kicking the tires and want to see what it's about. It also helps to streamline documentation, eliminating forks in the critical path and reducing decision fatigue.

What is this pull request doing?

This PR adds a new --quickstart flag to the init command. With no further user input required, it scaffolds a new Hydrogen project with the following defaults (which are the same ones we currently recommend, but which need to be selected manually by the user):

Option	Value
Storefront/data source	Mock.shop
Project name and path	./hydrogen-quickstart
Language	JavaScript
CSS library	Tailwind
Install dependencies?	Yes
Install h2 alias?	Yes
Scaffold standard routes?	Yes
Enable Markets support?	No

While these are the defaults, you can still override each option if you pass their respective flags with the quickstart flag.

How to test your changes? 🎩

1. Checkout the branch
2. In the monorepo, run npx shopify hydrogen init --quickstart
3. Validate that a new Hydrogen project is scaffolded at ./hydrogen-quickstart.
4. Also try overrides with individual flags. For example, TypeScript: npx shopify hydrogen init --quickstart --language ts

🎬

quickstart.mp4

Update: Also resolved the double-success-banner issue, and removed extraneous help links from the final succcess message:

Todos

• Tests — probably need an assist here
• Documentation updates should ship in parallel

[shopify]

Oxygen deployed a preview of your gfscott-quickstart branch. Details:

Storefront	Status	Preview link	Deployment details	Last update (UTC)
custom-cart-method	✅ Successful (Logs)	Preview deployment	Inspect deployment	March 13, 2024 1:57 PM
subscriptions	✅ Successful (Logs)	Preview deployment	Inspect deployment	March 13, 2024 1:57 PM
third-party-queries-caching	✅ Successful (Logs)	Preview deployment	Inspect deployment	March 13, 2024 1:57 PM
vite	✅ Successful (Logs)	Preview deployment	Inspect deployment	March 13, 2024 1:57 PM
skeleton	✅ Successful (Logs)	Preview deployment	Inspect deployment	March 13, 2024 1:57 PM
optimistic-cart-ui	✅ Successful (Logs)	Preview deployment	Inspect deployment	March 13, 2024 1:57 PM

Learn more about Hydrogen's GitHub integration.

[frandiox]

Looks good! ✅
Remember to add a changeset 🙏