Default endpoint as main page

[tkiapril]

The main page should be an endpoint summary page with default endpoint as the main page.
There should be a mechanism to retrieve the default main page from a static file in the public/ directory.
The file should be generated on build/export, and measures to decide on a default endpoint on the environment variable must be provided.
A static endpoint given as a slug must be redirected to the top level pages if the given static endpoint is the default endpoint.