"User docs" filter not working properly

There is something not quite right about the search results when you select User docs.

Repro steps:

1. Search for secret.
2. Select See all results at the bottom of the list.
3. Filter by User docs checkbox (on left).

• Actual result: You get pages that are all about subscribe and tutorials
• Expected: You should get pages under "use gitlab" first, because they're probably more popular? The results should be a blend of pages from all of these areas, with the most relevant results coming first.