Every article carries extra keywords covering how people actually phrase a question, not just what we named the feature. Searching "why is my music louder than the dialogue" finds the ducking article even though it contains none of those words in its title.
Results are ranked by where the match landed — an exact phrase in a title outranks a scattered term match in a body — and each result shows why it matched.
You can also browse by category if you would rather look around than ask.
If a search finds nothing useful it is recorded (just the query, and your account if you are signed in), so gaps in the documentation become visible instead of silently frustrating people.