MAPREDUCE-3136. Added the missing link to index.html.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1184981 13f79535-47bb-0310-9956-ffa450edef68

hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-site/src/site/apt/index.apt.vm

@@ -41,6 +41,8 @@ Hadoop MapReduce Next Generation
 
   * {{{./SingleCluster.html}Setting up a Single Node Cluster}}
 
+  * {{{./ClusterSetup.html}Setting up a full-fledged Hadoop Cluster}}
+  
   * {{{./apidocs/index.html}JavaDocs}}
 
   * {{{./WritingYarnApplications.html}Writing Yarn Applications}}