Create a simple giter8 template

[raquo]

Problem:

• People want to say sbt new raquo/laminar.g8 to get a clean new laminar project.

Scope:

• Probably a frontend-only setup, with build.sbt and vite dev server.
• No waypoint, no backend, no existing components except for easy-to-override hello world.

Implementation:

• Set up a new repo similar to https://github.com/scala/scala3.g8
• Link to it in quick start, laminar demo, docs, and the resources page
• This repo will need to be maintained separately from the full stack demo

[raquo]

MVP Done: https://github.com/raquo/scalajs.g8