documentation for using guard in the PDP

Added guardpdp.rst and minor updates to other documentation.
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Change-Id: If0d430cdff3b9b1700b773b78c3d951698609714
Issue-Id: POLICY-335
Signed-off-by: Saryu Shah <ss3917@att.com>
diff --git a/docs/platform/installation.rst b/docs/platform/installation.rst
index a10f026..cd9388f 100644
--- a/docs/platform/installation.rst
+++ b/docs/platform/installation.rst
@@ -313,3 +313,6 @@
 .. _Standalone Quick Start : https://wiki.onap.org/display/DW/ONAP+Policy+Framework%3A+Standalone+Quick+Start
 
 
+
+End of Document
+