Auto merge of #5328 - dwijnand:doc-links-key, r=matklad
authorbors <bors@rust-lang.org>
Mon, 9 Apr 2018 20:30:49 +0000 (20:30 +0000)
committerbors <bors@rust-lang.org>
Mon, 9 Apr 2018 20:30:49 +0000 (20:30 +0000)
Add a reference to the links key in the manifest docs

Fixes #4975


Trivial merge