Fix incorrent "response" in settings (#3115)

Author: ellnix

reference/api/settings.mdx

@@ -1172,9 +1172,7 @@ Get the facet search settings of an index.
 ##### Response: `200 OK`
 
 ```json
-{
-  "facetSearch": true
-}
+true
 ```
 
 ### Update facet search settings
@@ -1271,9 +1269,7 @@ Get the prefix search settings of an index.
 ##### Response: `200 OK`
 
 ```json
-{
-  "prefixSearch": "indexingTime"
-}
+"indexingTime"
 ```
 
 ### Update prefix search settings