Auto merge of #3438 - petrochenkov:bsdoc, r=alexcrichton
authorbors <bors@rust-lang.org>
Wed, 28 Dec 2016 20:39:45 +0000 (20:39 +0000)
committerbors <bors@rust-lang.org>
Wed, 28 Dec 2016 20:39:45 +0000 (20:39 +0000)
Add some more details to build script docs

r? @alexcrichton


Trivial merge