fix path in children

[ctholho]

nested routes may have two different ways to appear on the same route as their parent.

1. the exact same path (starting with a /)
2. an empty path

this PR changes the child route to an empty path, whereas before it was the same path. There used to be an error with vite-ssg that has since been fixed. This change would reflect a more explicit way that a page is child to a layout.

This PR also adds a path name to a route in the examples to show that you can still use names.

fixes #26

edit: still WIP

caveat: this creates a warning if you run example:build-ssg:
[Vue Router warn]: No match found for location with path "today"
But today.html page is still generated and works.

[ctholho]

ready to merge. see comments at #26 if this is necessary.