doc: add mention of the Go+ community

R=golang-dev, iant, kamil.kisiel, minux.ma
CC=golang-dev
https://golang.org/cl/7203049

doc/contrib.html

@@ -94,6 +94,9 @@ mailing list is for general Go discussion.</p>
 <h3 id="irc"><a href="irc:irc.freenode.net/go-nuts">Go IRC Channel</a></h3>
 <p><b>#go-nuts</b> on <b>irc.freenode.net</b> is the official Go IRC channel.</p>
 
+<h3 id="pluscom"><a href="https://plus.google.com/communities/114112804251407510571">The Go+ community</a></h3>
+<p>The Google+ community for Go enthusiasts.</p>
+
 <h3 id="plus"><a href="https://plus.google.com/101406623878176903605/posts">The Go Programming Language at Google+</a></h3>
 <p>The Go project's Google+ page.</p>
 

doc/help.html

@@ -28,11 +28,17 @@ archives and consult the <a href="/doc/go_faq.html">FAQ</a> and
 <p>Get live support at <b>#go-nuts</b> on <b>irc.freenode.net</b>, the official
 Go IRC channel.</p>
 
+<h3 id="pluscom"><a href="https://plus.google.com/communities/114112804251407510571">The Go+ community</a></h3>
+<p>The Google+ community for Go enthusiasts.</p>
+
+<h3 id="plus"><a href="https://plus.google.com/101406623878176903605/posts">The Go Programming Language at Google+</a></h3>
+<p>The Go project's Google+ page.</p>
+
 <h3 id="twitter"><a href="http://twitter.com/go_nuts">@go_nuts at Twitter</a></h3>
 <p>The Go project's official Twitter account.</p>
 <p>Tweeting your about problem with the <code>#golang</code> hashtag usually
 generates some helpful responses.</p>
 
-<h3 id="plus"><a href="https://plus.google.com/101406623878176903605/posts">The Go Programming Language at Google+</a></h3>
-<p>The Go project's Google+ page.</p>
-
+<h3 id="blog"><a href="http://blog.golang.org/">The Go Blog</a></h3>
+<p>The official blog of the Go project, featuring news and in-depth articles by
+the Go team and guests.</p>