Provide change summary before details for all gems

Update announcement template to have summary of changes since previous release before the details for each gem.

tasks/release_announcement_draft.erb

@@ -11,16 +11,16 @@ If you find one, please open an [issue on GitHub](https://github.com/rails/rails
 
 ## CHANGES since <%= version.previous %>
 
+To see a summary of changes, please read the release on GitHub:
+
+<%= "[#{version} CHANGELOG](https://github.com/rails/rails/releases/tag/v#{version})" %>
+
 To view the changes for each gem, please read the changelogs on GitHub:
 <% FRAMEWORKS.sort.each do |framework| %>
 <%= "* [#{FRAMEWORK_NAMES[framework]} CHANGELOG](https://github.com/rails/rails/blob/v#{version}/#{framework}/CHANGELOG.md)" %>
 
 <% end %>
 
-To see a summary of changes, please read the release on GitHub:
-
-<%= "[#{version} CHANGELOG](https://github.com/rails/rails/releases/tag/v#{version})" %>
-
 
 *Full listing*