Update openconfig-extensions.yang: review comment

Addressed review comments

release/models/openconfig-extensions.yang

@@ -171,12 +171,12 @@ module openconfig-extensions {
       model. For example, all elements under the subtree may be updated
       as a result of a new alarm being raised, or the arrival of a new
       protocol message. When the annotation is specified in the context
-      of a list of containers, it applies to individual list elements
-      (subtree or container and all elements under that subtree) of the
-      list and not to the entire list. For example, say ipv4-entry list
-      has two elements, prefix1 and prefix2, all elements under the
-      prefix1 subtree may be updated as a result of a next-hop group
-      change while prefix2 subtree is not updated.
+      of a list of containers, the atomic property applies to the
+      contents of each individual keyed entry in the list. For example,
+      say ipv4-entry list has two elements, prefix1 and prefix2, all 
+      the elements under the prefix1 subtree may be updated as a
+      result of a next-hop group change while prefix2 subtree is not
+      updated.
 
       Transport protocols may use the atomic specification to determine
       optimisations for sending or storing the corresponding data.";