Improve promts, turn confirms into toggle

[TheWolfNL]

Before submitting the PR, please make sure you do the following

• It's really useful if your PR references an issue where it is discussed ahead of time. In many cases, features are absent for a reason. For large changes, please create an RFC: https://github.com/sveltejs/rfcs
• This message body should clearly illustrate what problems it solves.

  This change will make it obvious what the default values are, and what the alternatives are.
  I found myself having to run the init multiple times since the default was not obvious or I 'entered' past it 😅
  The resulting values remain the same as before the change.
  
  Use arrow keys/tab/space to switch between options, enter to select.

• Ideally, include a test that fails without this PR but passes with it.

Tests

• Run the tests with pnpm test
• Lint the project with pnpm lint

Changesets

• If your PR makes a change that should be noted in one or more packages' changelogs, generate a changeset by running pnpx changeset and following the prompts

[Rich-Harris]

thanks!