Delete SiteBuilder.ts

[breck7]

Now that we are a dynamic site and not static, SiteBuilder.ts can be refactored out simplifying a lot.

[ghost]

dynamic scroll HOWTO would be nice to document :)

[breck7]

SiteBuilder.ts is gone! Still a little bit of a build step but much better.

@tomdseo any luck on Scroll docs? If you get those live I can add a section on using Scroll in dynamic sites to answer @SRS-WRKS 's request.