sphinx_local replica-set-secondary page

Author: Kay Kim

config/sphinx_local.yaml

@@ -45,6 +45,7 @@ theme:
     - /core/replica-set-architectures
     - /core/replica-set-high-availability
     - /core/replica-set-members
+    - /core/replica-set-secondary
     - /geospatial-queries
     - /replication
     - /core/sharded-cluster-components