What we need to do for layouts is decide upon the minimal necessary:

* Boilerplate to inject into the main index file from <layoutname>/index.html
* Files we additionally need to include for the layout. We should try to limit the number of files to be added as much as possible.
* Link up the layouts to use the final location where the dependencies for these parts are going to exist, so that we don't need to rely on static versions in the repo.

