[Docs] Clarify accepted sort case
Rescore only works with an explicite "sort" element if it is on descending
"_score". Even using "order" : "asc" will throw an error.
@@ -15,8 +15,8 @@ Currently the rescore API has only one implementation: the query
rescorer, which uses a query to tweak the scoring. In the future,
alternative rescorers may be made available, for example, a pair-wise rescorer.
-NOTE: An error will be thrown if an explicit <<search-request-sort,`sort`>> (other than `_score`)
-is provided with a `rescore` query.
+NOTE: An error will be thrown if an explicit <<search-request-sort,`sort`>>
+(other than `_score` in descending order) is provided with a `rescore` query.
NOTE: when exposing pagination to your users, you should not change
`window_size` as you step through each page (by passing different
