Documentation, add examples of using an Enum scope

When scanning the Enum API page I found it easy to miss that scopes are generated.  Adding an example clarifies use and has more... *pop*...

1 files changed, 4 insertions, 2 deletions

diff --git a/activerecord/lib/active_record/enum.rb b/activerecord/lib/active_record/enum.rb
index 18f1ca26de..c7ec093824 100644
--- a/activerecord/lib/active_record/enum.rb
+++ b/activerecord/lib/active_record/enum.rb
@@ -27,8 +27,10 @@ module ActiveRecord
   #   conversation.status      # => nil
   #
   # Scopes based on the allowed values of the enum field will be provided
-  # as well. With the above example, it will create an +active+ and +archived+
-  # scope.
+  # as well. With the above example:
+  #
+  #   Conversation.active
+  #   Conversation.archived
   #
   # You can set the default value from the database declaration, like:
   #