docs: gpstop new option --host (#4069)

* docs: gpstop new option --host

* docs: gpstop - update update/clarify --host description based on review comments.

* docs: gpstop --host. updates based on review comments.

* docs: gpstop - added information on restoring segments after using --host.

* docs: gpstop --host. corrected name of utility to recover segments : gprecoverseg.

gpdb-doc/dita/utility_guide/admin_utilities/gpstop.xml

@@ -16,6 +16,9 @@
 
 <b>gpstop</b> <b>-u</b> [<b>-d</b> <varname>master_data_directory</varname>] [<b>-l</b> <varname>logfile_directory</varname>] [<b>-v</b> | <b>-q</b>]
  
+<b>gpstop</b> <b>--host</b> <varname>host_name</varname> [<b>-d</b> <varname>master_data_directory</varname>] [<b>-l</b> <varname>logfile_directory</varname>]
+       [<b>-t</b> <varname>timeout_seconds</varname>] [<b>-a</b>] [<b>-v</b> | <b>-q</b>]
+
 <b>gpstop</b> <b>--version</b> 
 
 <b>gpstop</b> <b>-?</b> | <b>-h</b> | <b>--help</b></codeblock>
@@ -57,6 +60,26 @@
                     <pd>Optional. The master host data directory. If not specified, the value set
                         for <codeph>$MASTER_DATA_DIRECTORY</codeph> will be used.</pd>
                 </plentry>
+                <plentry>
+                    <pt>--host <varname>host_name</varname></pt>
+                    <pd>The utility shuts down the Greenplum Database segment instances on the
+                        specified host to allow maintenance on the host. Each primary segment
+                        instance on the host is shut down and the associated mirror segment instance
+                        is promoted to a primary segment if the mirror segment is on another host.
+                        Mirror segment instances on the host are shut down.</pd>
+                    <pd>The segment instances are not shut down and the utility returns an error in
+                        these cases:<ul id="ul_at2_kk3_ccb">
+                            <li>Segment mirroring is not enabled for the system.</li>
+                            <li>The master or standby master is on the host.</li>
+                            <li>Both a primary segment instance and its mirror are on the host.</li>
+                        </ul></pd>
+                    <pd>This option cannot be specified with the <codeph>-m</codeph>,
+                            <codeph>-r</codeph>, <codeph>-u</codeph>, or <codeph>-y</codeph>
+                            options.<note>The <codeph>gprecoverseg</codeph> utility restores segment
+                            instances. Run <codeph>gprecoverseg</codeph> commands to start the
+                            segments as mirrors and then to return the segments to their preferred
+                            role (primary segments). </note></pd>
+                </plentry>
                 <plentry>
                     <pt>-l <varname>logfile_directory</varname></pt>
                     <pd>The directory to write the log file. Defaults to