fix: move title from h3 to h2

Co-authored-by: Kévin Dunglas <kevin@dunglas.fr>

Author: vinceAmstoutz

core/elasticsearch-filters.md

@@ -121,7 +121,7 @@ Given that the collection endpoint is `/tweets`, you can filter tweets by messag
 
 `/tweets?message=Hello%20World` will return all tweets that match the text `Hello World`.
 
-### Term Filter
+## Term Filter
 
 The term filter allows us to find resources that contain the exact specified
 [terms](https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-term-query.html).