HBASE-20688 Refguide has HBase Backup section and a chapter named Backup and Restore; neither refers to the other (#562)

Signed-off-by: Jan Hentschel <jan.hentschel@ultratendency.com>
Signed-off-by: stack <stack@duboce.net>

Author: rabi-kumar

src/main/asciidoc/_chapters/ops_mgt.adoc

@@ -2789,7 +2789,7 @@ Since the cluster is up, there is a risk that edits could be missed in the copy
 The <<export,export>> approach dumps the content of a table to HDFS on the same cluster.
 To restore the data, the <<import,import>> utility would be used.
 
-Since the cluster is up, there is a risk that edits could be missed in the export process.
+Since the cluster is up, there is a risk that edits could be missed in the export process. If you want to know more about HBase back-up and restore see the page on link:http://hbase.apache.org/book.html#backuprestore[Backup and Restore].
 
 [[ops.snapshots]]
 == HBase Snapshots