Note: All docs get "flattened" and added to a single docs (entries) array.
What properties does a collection support?
- label =>
- docs => (not working if accessed with literal e.g. site.chapters instead of site.collections[0] - why?)
- files => note: only "static" files w/o front matter (e.g. yaml block/header)
What properties does a document support?
- path
- relative_path