Add links in cookbook for continuous_redrawing_of_views content

PR: https://github.com/emberjs/website/pull/728 was missing the links to the cookbook content (for continuous_redrawing_of_views) 

PR #728 was originally created from the cookbook branch and merged to master, so the links in the sidebar and on the guides/cookbook/working_with_objects page were not present in the master branch.

This change adds the links in the sidebar and on the index page: `guides/cookbook/working_with_objects` for the content
"Continuous Redrawing of Views" at: "cookbook/working_with_objects/continuous_redrawing_of_views"