I was kind of confused as to the organization of the repos and how this is all brought together. Is there a document somewhere explaining the relationship (hier

I was kind of confused as to the organization of the repos and how this is all brought together. Is there a document somewhere explaining the relationship (hierarchy) of all the repos and what role each plays in the larger polymer material project? Specifically, where is the code that does the layout for this? I want to see how they are doing the positioning of elements in space. Is it all CSS classes or do they do positioning with javascript?