[DOCS] Correct the documented behaviour of `track_total_hits` (#62837) (#62866)

If `track_total_hits=true` is used, the exact value of the number of hits is returned - i.e. the value is effectively limitless, and not the default value of 10,000

Co-authored-by: AndyHunt66 <andrew.hunt@elastic.co>

docs/reference/search/search.asciidoc

@@ -288,7 +288,7 @@ the scores are not used for sorting. Defaults to `false`.
 (Optional, integer or boolean)
 Number of hits matching the query to count accurately. Defaults to `10000`.
 +
-If `true`, the default value is used. If `false`, the response does not
+If `true`, the exact number of hits is returned. If `false`, the response does not
 include the total number of hits matching the query.
 
 `typed_keys`::