DOCS-3227: added 2.6 note to this page.

Signed-off-by: kay <[email protected]>

Author: TimSlavinMongoDB

source/tutorial/build-indexes-on-replica-sets.txt

@@ -118,6 +118,11 @@ Allow replication to catch up on this member.
 Build Indexes on all Secondaries
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
+.. versionchanged:: 2.6
+   Secondary members can now :doc:`build indexes in the background 
+   </tutorial/build-indexes-in-the-background>`. Previously all index builds on secondaries were in 
+   the foreground.
+
 For each secondary in the set, build an index according to the
 following steps: