docs: update instructions for synthetic source (#3823)

axw · web-flow · commit 362e78ea5e84 · 2022-07-26T08:12:22.000+02:00
See elastic/elasticsearch#88211
diff --git a/docs/how_to_test_new_indexing_features.md b/docs/how_to_test_new_indexing_features.md
@@ -22,7 +22,7 @@ PUT /_component_template/metrics-nginx.substatus@custom
     "settings": {},
     "mappings": {
       "_source": {
-        "synthetic": true
+        "mode": "synthetic"
       }
     }
   },

Original file line number	Diff line number	Diff line change
`@@ -22,7 +22,7 @@ PUT /_component_template/metrics-nginx.substatus@custom`
`22`	`22`	`"settings": {},`
`23`	`23`	`"mappings": {`
`24`	`24`	`"_source": {`
`25`		`- "synthetic": true`
	`25`	`+ "mode": "synthetic"`
`26`	`26`	`}`
`27`	`27`	`}`
`28`	`28`	`},`