how do you add categories such as slug and article depth to the search result list?

Bill are you talking about in the admin or in front-end search results?

If Admin, it depends on if you are using NXT or Legacy:

In Legacy in Editorial Assets, hover over one of the columns along the top, like Title. On the right side of the column header you'll see a dropdown arrow appear. click that and you'll see a list of columns available. You can also click on a column and drag reorder it.

In NXT, hover in the header area and you'll see 3 vertical dots on the right of the column header. Click that and then 'manage columns'.