Only the latest group marked as featured appears in the landing page #29

When selecting featured groups and organizations to show in the landing page, the latest selected group or organization takes the place of the previous marked as featured. However, it doesn't remove the is_featured check mark from the previous featured group. This behavior makes it difficult to track all groups and organizations that have still the is_featured field checked. The expected behavior would be that if a new group or organization is added to the featured list, it will stay on the landing page until is_featured is unchecked.