docs - misc pxf content and book edits (#6155)

gpdb-doc/book/master_middleman/source/subnavs/pxf-subnav.erb

@@ -11,20 +11,28 @@
           <li>
             <a href="/docs/600/pxf/intro_pxf.html" format="markdown">PXF Architecture</a>
           </li>
+          <li>
+            <a href="/docs/600/pxf/about_pxf_dir.html" format="markdown">About the PXF Installation Directories</a>
+          </li>
           <li class="has_submenu">
-            <a href="/docs/600/pxf/instcfg_pxf.html" format="markdown">Installing and Configuring PXF</a>
+            <a href="/docs/600/pxf/instcfg_pxf.html" format="markdown">Configuring PXF</a>
             <ul>
               <li>
-                <a href="/docs/600/pxf/client_instcfg.html" format="markdown">Installing and Configuring Hadoop Clients for PXF</a>
+                <a href="/docs/600/pxf/install_java.html" format="markdown">Installing Java for PXF</a>
               </li>
-              <li>
-                <a href="/docs/600/pxf/pxfuserimpers.html">Configuring User Impersonation and Proxying</a>
-              </li>
-              <li>
-                <a href="/docs/600/pxf/cfginitstart_pxf.html" format="markdown">Configuring, Initializing, and Managing PXF</a>
+              <li class="has_submenu">
+                <a href="/docs/600/pxf/client_instcfg.html" format="markdown">Configuring PXF Hadoop Connectors (Optional)</a>
+                <ul>
+                  <li>
+                    <a href="/docs/600/pxf/pxfuserimpers.html">Configuring User Impersonation and Proxying</a>
+                  </li>
+                  <li>
+                    <a href="/docs/600/pxf/pxf_kerbhdfs.html" format="markdown">Configuring PXF for Secure HDFS</a>
+                  </li>
+                </ul>
               </li>
               <li>
-                <a href="/docs/600/pxf/pxf_kerbhdfs.html" format="markdown">Configuring PXF for Secure HDFS</a>
+                <a href="/docs/600/pxf/cfginitstart_pxf.html" format="markdown">Initializing and Managing PXF</a>
               </li>
             </ul>
           </li>

gpdb-doc/markdown/pxf/client_instcfg.html.md.erb

 ---
-title: Configuring PXF Hadoop Connectors
+title: Configuring PXF Hadoop Connectors (Optional)
 ---
 
 PXF is compatible with Cloudera, Hortonworks Data Platform, and generic Apache Hadoop distributions. This topic describes how configure the PXF Hadoop, Hive, and HBase connectors.

gpdb-doc/markdown/pxf/pxf_kerbhdfs.html.md.erb

@@ -10,7 +10,7 @@ When Kerberos is enabled for your HDFS filesystem, PXF, as an HDFS client, requi
 
 Before you configure PXF for access to a secure HDFS filesystem, ensure that you have:
 
-- Configured, initialized, and started PXF as described in [Installing and Configuring PXF](instcfg_pxf.html), including enabling PXF and Hadoop user impersonation.
+- Configured, initialized, and started PXF as described in [Configuring PXF](instcfg_pxf.html), including enabling PXF and Hadoop user impersonation.
 
 - Enabled Kerberos for your Hadoop cluster per the instructions for your specific distribution and verified the configuration.
 

gpdb-doc/markdown/pxf/sdk/deploy_conn.html.md.erb

@@ -94,7 +94,7 @@ Before attempting this exercise, ensure that you have:
 
 - Built the *Demo* connector as described in [Example: Building the Demo Connector JAR File](build_conn.html#demo_buildjar).
 - Administrative access to a running Greenplum Database cluster.
-- Installed the Hadoop clients and initialized and started the PXF agent on each Greenplum Database segment host as described in [Installing and Configuring PXF](https://gpdb.docs.pivotal.io/latest/pxf/instcfg_pxf.html).
+- Initialized, configured, and started the PXF agent on each Greenplum Database segment host as described in [Configuring PXF](https://gpdb.docs.pivotal.io/latest/pxf/instcfg_pxf.html).
 - Enabled the PXF extension in the database, and optionally granted specific Greenplum Database roles access to the `pxf` protocol; [Enabling/Disabling PXF](https://gpdb.docs.pivotal.io/latest/pxf/using_pxf.html#enable-pxf-ext) and [Granting Access to PXF](https://gpdb.docs.pivotal.io/latest/pxf/using_pxf.html#access_pxf) describe these procedures.
 
 ### <a id="procedure"></a>Procedure