Add note on orca adding attribution

src/main/docbkx/book.xml

@@ -5647,6 +5647,24 @@ DESCRIPTION                                          ENABLED
          </para>
        </section>
   </appendix>
+  <appendix xml:id="orca">
+    <title>Apache HBase Orca</title>
+        <inlinemediaobject>
+          <imageobject>
+            <imagedata
+              align="center"
+              valign="right"
+              fileref="jumping-orca_rotated_25percent.png" />
+          </imageobject>
+        </inlinemediaobject>
+    <para><link xlink:href="https://issues.apache.org/jira/browse/HBASE-4920">An Orca is the Apache HBase mascot.</link>
+      See NOTICES.txt.  Our Orca logo we got here: http://www.vectorfree.com/jumping-orca
+      It is licensed Creative Commons Attribution 3.0.  See https://creativecommons.org/licenses/by/3.0/us/
+      We changed the logo by stripping the colored background, inverting
+      it and then rotating it some.
+    </para>
+    
+  </appendix>
 
   <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="tracing.xml" />
   <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="rpc.xml" />