Jekyll Liquid API
Jekyll uses the standard Liquid templating language package and includes a few other helpful extensions of its own. Jekyll-bootstrap does not support plugin development so only the standard filters and logic will be available to us.
Remember we are the end-users!
Liquid Crash Course
The following link contains a comprehensive course in everything available in Liquid. The standard library is also available in Jekyll.
Liquid Extensions Provided With Jekyll
Jekyll introduces a few other filters and tags as outlined here: