split default recommend per search+index

docs/reference/index-modules/slowlog.asciidoc

@@ -232,18 +232,29 @@ optimization information, see <<tune-for-search-speed,tune for search speed>>
 and <<tune-for-indexing-speed,tune for indexing speed>.
 
 If you are uncertain where to begin investigating problematic traffic, we
-recommend dynamically enabling via <<indices-update-settings,update indices
-settings>> with high thresholds against both slow logs:
+recommend dynamically enabling the `warn` threshold with a high `30s` threshold
+via <<indices-update-settings,update indices settings>>. For slow logs for
 
+* search
++
 [source,console]
 --------------------------------------------------
 PUT _all/_settings
 {
-  "index.indexing.slowlog.include.user": true
-  "index.indexing.slowlog.threshold.index.warn": "30s",
   "index.search.slowlog.include.user": true
   "index.search.slowlog.threshold.fetch.warn": "30s",
-  "index.search.slowlog.threshold.query.warn": "30s",
+  "index.search.slowlog.threshold.query.warn": "30s"
+}
+--------------------------------------------------
+
+* indexing
++
+[source,console]
+--------------------------------------------------
+PUT _all/_settings
+{
+  "index.indexing.slowlog.include.user": true
+  "index.indexing.slowlog.threshold.index.warn": "30s"
 }
 --------------------------------------------------