docs/64934: [patch] add new article to docs, FreeBSD Mailing List FAQ

[Mark Linimon]

A further note that was lost in a previous edit mistake: the links
in this article to the www tree do not appear to work properly on my
machine.  I have included XXX comments to point these out.  However,
I should note that I copied their content over from other articles
at a similar level in the tree.  Someone with more experience with
the structure of the doc vs www trees will have to vet this.