We just merged a PR that adds a minimal structure for a user guide in mdbook format, based on the existing Ballista user guide.
https://github.com/apache/arrow-datafusion/tree/master/docs/user-guide It should now be simple for anyone to contribute to this for end-user documentation for DataFusion and Ballista and we can publish this when we make the next release. There is an open issue for discussing how and where we publish this [1]. Thanks, Andy. [1] https://github.com/apache/arrow-datafusion/issues/18
