Add transition support library to docs path to fix build

Change-Id: I277df6af728aea4aaa5b10605cf2a6a44c2a246f
diff --git a/core/pathmap.mk b/core/pathmap.mk
index edc584b..effc878 100644
--- a/core/pathmap.mk
+++ b/core/pathmap.mk
@@ -121,6 +121,7 @@
         design \
         percent \
         recommendation \
+        transition \
         v7/preference \
         v14/preference \
         v17/preference-leanback \