Skip templating when creating policy file in workspace root. Allow disabling templating.

[anderseknert]

We currently create a "main" directory for this and move it there. This has rightly been perceived as confusing, and there's nothing in this process that provides a clue as to why this happened. We could add a comment or something like that in the template, but a simpler approach is to just skip templating in the workspace root. This will instead flag a violation, giving users a chance to learn about it, and disable it if they so want.

On the topic of disabling, we should also allow disabling templating altogether.