Update SD-Core configuration document

Change-Id: I652f55824775bd7be2d2dfed1ac835af4a3ca3d8
diff --git a/dict.txt b/dict.txt
index 96a5cf9..6913ce1 100644
--- a/dict.txt
+++ b/dict.txt
@@ -198,3 +198,4 @@
 opencord
 configs
 gnbsim
+apn