Publish documentation for Python bindings

[luk-f-a]

hi, I might have missed something, but there's no link on the github repo to the python documentation, and some quick googling points to https://arrow.apache.org/datafusion/python/index.html which returns "Not Found The requested URL was not found on this server.".

The main github page points to arrow.apache.org/datafusion but there's no python section there.

I hope I am not wasting your time by missing something obvious.

[andygrove]

Hi @luk-f-a we plan on fixing this for the upcoming 0.7.0 release (#7)

[andygrove]

Once the release vote passes tomorrow, I can publish the documentation to the Arrow web site.

The main DataFusion documentation is published at: https://arrow.apache.org/datafusion/

I plan on publishing the documentation for the Python bindings to https://arrow.apache.org/datafusion-python/ unless there are any objections.

[andygrove]

apache/arrow-site#279