Yeah, you definitely need a "What are pipelines?" section. From looking over the examples, my impression is this is some kind of job scheduler, like sidekiq.
Some might opine that having to search through upwards of 75% of the length of a page before finding out what problem a tool addresses is a situation possessed of wonderful and bountiful opportunity to become even clearer.
We have already defined a "Q&A" section in our github README file (https://github.com/gaia-pipeline/gaia#questions-and-answers-...). Does this briefly answer your question or is still too vague?