instructions
How to add a new file.
There was a submodule thing going on with github. Tried this:
git submodule update --init
Evidently, the submodule is a repository within a repository. I didn’t need the _theme_packages directory, which seems to have been the source of the problem. So, I deleted it.
Liquid Crash Course
The following link contains a comprehensive course in everything available in Liquid. The standard library is also available in Jekyll.
http://github.com/Shopify/liquid/wiki/Liquid-for-Designers
Liquid Extensions Provided With Jekyll
Jekyll introduces a few other filters and tags as outlined here: