Core classes in the Kobweb framework.

Kobweb sites will be required to use classes from this library, as the kobweb binary will use reflection to search for them in order to set up a bare minimum web server.

For example, Page is the base class for composable logic that will be converted into .html files, while App is a singleton which owns the state and configuration of the entire site (such as plugins and style / theming values).

This also contains composables for all the standard HTML components, albiet with a very standard and stark theme that most users will want to customize for their own site.