Auto merge of #5226 - jeehoonkang:doc-caret, r=alexcrichton
authorbors <bors@rust-lang.org>
Thu, 22 Mar 2018 18:48:48 +0000 (18:48 +0000)
committerbors <bors@rust-lang.org>
Thu, 22 Mar 2018 18:48:48 +0000 (18:48 +0000)
doc: Clarify the meaning of caret requirements

Closes #4910 (which is already closed, though ðŸ˜„)

r? @alexcrichton


Trivial merge