Add super-sitemap to SvelteKit'ssv CLI

[jasongitmail]

1. Install super-sitemap dependency.
2. Create sitemap.xml route.
3. Create robots.txt route.

Console log to tell user what just happened, and suggest user to set up a Playwright test, with link to docs: https://github.com/jasongitmail/super-sitemap#playwright-test We can't add this unless we know where playwright tests are stored, and the dev may not have even set up Playwright on their project, when creating their new SvelteKit project.

And See docs at: https://github.com/jasongitmail/super-sitemap

Blocked on support for community plugins within sv.