Besides the README.md to get started, the app defaults to a private portal with a component playground (for React), internal docs (for answering "how do I"), and tools for completely removing the need for doc pages at all.
I believe that documentation has to be part of the workflow, so component documentation should be visible while working on the component, tools for workflow should have introductions and helpful hints rather than being just forms and buttons, etc.
So far, this is proving fruitful.
(Side note: wikis are where docs go to die.)