Remove redundant menu_link_content from starter, along with datetime which is...

Remove redundant menu_link_content from starter, along with datetime which is installed by smart_date

Closes #3487074

recipes/drupal_cms_admin_theme/recipe.yml

@@ -3,6 +3,7 @@ type: Drupal CMS
 description: Sets up a nice administrative theme and navigation.
 install:
   - coffee
+  - contextual
   - gin
   - gin_toolbar
   - navigation