Fix file descriptor endpoint in configuration docs

The endpoint /_nodes/process does not show file descriptors, should be
/_nodes/stats/process.

Closes #16000

docs/reference/setup/configuration.asciidoc

@@ -44,7 +44,7 @@ using the <<cluster-nodes-info>> API, with:
 
 [source,js]
 --------------------------------------------------
-curl localhost:9200/_nodes/process?pretty
+curl localhost:9200/_nodes/stats/process?pretty
 --------------------------------------------------
 
 [float]