move index to appendices directory

diff --git a/1.6/bookindex.xml b/1.6/bookindex.xml
deleted file mode 100755 (executable)
index 261c6ec..0000000
--- a/1.6/bookindex.xml
+++ /dev/null
@@ -1,5 +0,0 @@
-<?xml version='1.0' encoding='UTF-8'?>
-<index xmlns='http://docbook.org/ns/docbook'>
-<title>Index</title>
-</index>
-