[DOCS] Add update API link to deployment NLP steps (elastic#2245)

Co-authored-by: István Zoltán Szabó <[email protected]>

Author: lcawl

docs/en/stack/ml/nlp/ml-nlp-deploy-models.asciidoc

@@ -152,7 +152,10 @@ increases the speed of {infer} requests. The value of this setting must not
 exceed the number of available allocated processors per node.
 
 You can view the allocation status in {kib} or by using the
-{ref}/get-trained-models-stats.html[get trained model stats API].
+{ref}/get-trained-models-stats.html[get trained model stats API]. If you to
+change the number of allocations, you can use the
+{ref}/update-trained-model-deployment.html[update trained model stats API] after
+the allocation status is `started`.
 
 [discrete]
 [[ml-nlp-test-inference]]