ZOOKEEPER-4355: ZK documentation side bar and welcome page are out of sync

* Added missing links to header.html
* Added a short description for hierarchical quorums section

Author: Nihal Jain <nihaljain.cs@gmail.com>

Reviewers: maoling <maoling@apache.org>, Damien Diederen <ddiederen@apache.org>

Closes #1740 from NihalJain/ZOOKEEPER-4355

zookeeper-docs/src/main/resources/markdown/html/header.html

@@ -75,6 +75,9 @@ document.write("Last Published: " + document.lastModified);
             <div class="menuitem">
                 <a href="zookeeperProgrammers.html">Programmer's Guide</a>
             </div>
+            <div class="menuitem">
+                <a href="zookeeperUseCases.html">Use Cases</a>
+            </div>
             <div class="menuitem">
                 <a href="javaExample.html">Java Example</a>
             </div>
@@ -96,11 +99,23 @@ document.write("Last Published: " + document.lastModified);
             <div class="menuitem">
                 <a href="zookeeperJMX.html">JMX</a>
             </div>
+            <div class="menuitem">
+                <a href="zookeeperHierarchicalQuorums.html">Hierarchical Quorums</a>
+            </div>
             <div class="menuitem">
                 <a href="zookeeperObservers.html">Observers Guide</a>
             </div>
             <div class="menuitem">
                 <a href="zookeeperReconfig.html">Dynamic Reconfiguration</a>
+            </div>
+            <div class="menuitem">
+                <a href="zookeeperCLI.html">ZooKeeper CLI</a>
+            </div>
+            <div class="menuitem">
+                <a href="zookeeperTools.html">ZooKeeper Tools</a>
+            </div>
+            <div class="menuitem">
+                <a href="zookeeperMonitor.html">ZooKeeper Monitor</a>
             </div>
 			<div class="menuitem">
                 <a href="zookeeperAuditLogs.html">Audit Logs</a>

zookeeper-docs/src/main/resources/markdown/index.md

@@ -47,7 +47,7 @@ archives.
     + [Administrator's Guide](zookeeperAdmin.html) - a guide for system administrators and anyone else who might deploy ZooKeeper
     + [Quota Guide](zookeeperQuotas.html) - a guide for system administrators on Quotas in ZooKeeper.
     + [JMX](zookeeperJMX.html) - how to enable JMX in ZooKeeper
-    + [Hierarchical quorums](zookeeperHierarchicalQuorums.html)
+    + [Hierarchical Quorums](zookeeperHierarchicalQuorums.html) - a guide on how to use hierarchical quorums
     + [Observers](zookeeperObservers.html) - non-voting ensemble members that easily improve ZooKeeper's scalability
     + [Dynamic Reconfiguration](zookeeperReconfig.html) - a guide on how to use dynamic reconfiguration in ZooKeeper
     + [ZooKeeper CLI](zookeeperCLI.html) - a guide on how to use the ZooKeeper command line interface