[WEBSITE] Hosting cookbook on arrow.apache.org

[Weston Pace <we...@gmail.com>]

After some discussion on [1] we are planning on publishing the Arrow
cookbook at https://arrow.apache.org/cookbook .  I figured I'd run
this by the ML real quick before I started publishing.  If you have
any thoughts or comments feel free to add them here or on [1].

I'll also note that the ASF Infra documentation is a little sparse on
the details of how this might work.  I've reached out from the Infra
team on Slack and been told that this sort of "subproject hosting"
should be possible.  Specifically, "if there is no overlap and the top
checkout is registered first, it will work".  My best guess at how to
do this is [2].  If anyone has an experience with ASF / site
integration I'd appreciate a quick sanity check.  I'll be watching it
closely to make sure it doesn't break anything on the main site.

[1] https://github.com/apache/arrow-cookbook/issues/9
[2] https://github.com/apache/arrow-cookbook/pull/30