Make templates actual executable tests to that we ensure there are no regressions.
It also makes the setup easier.
Also changes the layout to typescript because that's what we want to use by default anyway.
Also refactors helper function to use plop specific `{{ toFileName name }}` syntax for easier template modification.
Co-authored-by: JJ Kasper <22380829+ijjk@users.noreply.github.com>