A new new project flow

We've updated the flow for new projects so there's more direction on what you can do. We used to just put you on an empty canvas, but now there's a proper `/new` page that asks where you want to start before it goes off and creates anything. There are three new options:

• Import a GitHub repo, where you pick a repo and configure the build before deploying.
• Start from a template, and once you pick one and fill in any env vars it needs, you end up with a project that's already wired up.
• Start with an empty project, which is the same path it always was for getting to a blank canvas.

This is all available from an unauthenticated state, so you can start adding "Deploy to Suga" buttons to all your project READMEs.