These are Sphinx docs, automatically built at http://docs.wagtail.io when the master branch is committed to Github. To build them locally, install Wagtail's development requirements (in the root Wagtail directory):
pip install -e .[testing,docs]
To build the documentation for browsing, from this directory run:
make html
then open _build/html/index.html in a browser.
To rebuild automatically while editing the documentation, from this directory run:
sphinx-autobuild . _build
The online editor at http://rst.ninjs.org/ is a helpful tool for checking reStructuredText syntax.