Updating setup instructions

This pull request gives instructions for creating a workshop website, based on those in `swcarpentry/bc`.

* It incorporates the changes in #3 (because it needed those updated page templates to render properly).
* It references the workshop creation script in #5.
In the first list you have number + dot + some spaces and the text start at the 5th column. Here you have number + dot + one space and the text start right after the space.