They didn't get their own category after the migration like they used to have, but they were moved over to the product categories with the tag "tech_tips". If you go to the content page, you can click the "Filter by tag" button and then filter on tech_tips to find them. We are discussing with the IM team to have all new tech tips posted as documents to set them apart from the other discussions. They would be in the same place then as the wiki content.