ASF supports enabling GitHub pages via asf.yaml [1] and we could consider using this to publish end user documentation for DataFusion and Ballista.

Ballista already has a minimal user guide in mdbook format that is part of this repo [2] and is currently published to https://ballistacompute.org/docs/ but it would be better to publish it here as part of the DataFusion user guide?

[1] https://cwiki.apache.org/confluence/display/INFRA/git+-+.asf.yaml+features
[2] https://github.com/apache/arrow-datafusion/tree/master/ballista/docs/user-guide