Add docs for SD-Core testing

Change-Id: Ibdc68e1f907b570da2c932ef500f5d532f869d6c
diff --git a/index.rst b/index.rst
index bcd7be7..bd77ca9 100644
--- a/index.rst
+++ b/index.rst
@@ -45,6 +45,7 @@
    testing/acceptance_specification
    testing/pdp_testing
    testing/fabric_testing
+   testing/sdcore_testing
 
 .. toctree::
    :maxdepth: 1