Tell Windows users how to update Mercurial's library.zip to add some missing dependencies.
Fixes #4745.
R=golang-dev, patrick.allen.higgins, minux.ma, adg
CC=golang-dev
https://golang.org/cl/
7558043
document assumes you are inside <code>$GOROOT</code> when issuing commands.
</p>
+<p>
+Windows users may need to perform extra steps to get the code review
+extension working. See the
+<a href="https://code.google.com/p/go-wiki/wiki/CodeReview">CodeReview page</a>
+on the <a href="http://code.google.com/p/go-wiki/wiki">Go Wiki</a> for details.
+</p>
+
<h3>Log in to the code review site.</h3>
<p>