WP2 vocabulary fix: models to modules

Created by: IgnacioHeredia

This pull request aims to complete #25 by including the new WP2 vocabulary (modules=models+services) also in the html templates (and not only in the content markdown files).

This means that mentions to models in the templates have been changes to modules.

All changes are inside a single commit as they are all interelated (eg. templates depend also on css, thus changes on both are put inside the same commit), thus making a single logical change.

Before:

After: