refactor: Get the taxonomy support back to a functional state. There's now a taxonomy content source that wraps another normal content source like a blog posts' source. It works in tandem with a taxonomy content pipeline that will do the heavy lifting of figuring out what kind of terms exist and need to be baked.

site:
    root: /piecrust/v2/
baker:
    assets_dirs:
        assets:
            processors: all