doc: tidy up "Projects" page; add Go 1.4

LGTM=r
R=r
CC=golang-codereviews
https://golang.org/cl/182750043

doc/contrib.html

@@ -30,21 +30,16 @@ We encourage all Go users to subscribe to
 <h2 id="go1">Version history</h2>
 
 <h3 id="release"><a href="/doc/devel/release.html">Release History</a></h3>
-<p>A summary of the changes between Go releases.</p>
 
-<h4 id="go1notes"><a href="/doc/go1">Go 1 Release Notes</a></h4>
-<p>
-A guide for updating your code to work with Go 1.
-</p>
+<p>A <a href="/doc/devel/release.html">summary</a> of the changes between Go releases. Notes for the major releases:</p>
 
-<h4 id="release notes"><a href="/doc/go1.1">Go 1.1 Release Notes</a></h4>
-<p>
-A list of significant changes in Go 1.1, with instructions for updating
-your code where necessary.
-Each point release includes a similar document appropriate for that
-release: <a href="/doc/go1.2">Go 1.2</a>, <a href="/doc/go1.3">Go 1.3</a>,
-and so on.
-</p>
+<ul>
+	<li><a href="/doc/go1.4">Go 1.4</a> <small>(December 2014)</small></li>
+	<li><a href="/doc/go1.3">Go 1.3</a> <small>(June 2014)</small></li>
+	<li><a href="/doc/go1.2">Go 1.2</a> <small>(December 2013)</small></li>
+	<li><a href="/doc/go1.1">Go 1.1</a> <small>(May 2013)</small></li>
+	<li><a href="/doc/go1">Go 1</a> <small>(March 2012)</small></li>
+</ul>
 
 <h3 id="go1compat"><a href="/doc/go1compat">Go 1 and the Future of Go Programs</a></h3>
 <p>