[DOCS] Fix heading in create ingest pipeline API docs

Author: jrodewig

docs/reference/ingest/apis/put-pipeline.asciidoc

@@ -44,8 +44,8 @@ PUT _ingest/pipeline/my-pipeline-id
 include::{docdir}/rest-api/common-parms.asciidoc[tag=master-timeout]
 
 
-[[put-pipeline-api-response-body]]
-==== {api-response-body-title}
+[[put-pipeline-api-request-body]]
+==== {api-request-body-title}
 
 `description`::
 (Required, string)