It has not moved. I did update the documentation recently for the latest release. It seems to be there:
Can you be more specific about what page you are trying to access? Maybe it was a transient server issue.
actually have the docs pre-generated in them; see slate/docs/html/index.html
You can also generate the docs using `make docs` if you have doxygen installed.
The docs website might move soon, but we'll post new links if that happens, and redirect the old pages.