Don't copy Handlebars.templates from Thorax.templates

This PR comes about for several reasons. Several users have been confused if `Thorax.templates` is something different than the `Handlebars.template` hash, which it is not. I don't see a reason to copy it, and by default the handlebars bin task will generate a `Handlebars.templates` hash which with this PR would require no changes for Thorax to work with the generated file outside of Lumbar projects.

This PR has no side effects on projects using Thorax as a component as the only reference to `Thorax.templates` is in the `lumbar.json` in this repo.