Release note, api-ref for event list nested_depth

To document the feature for the spec-lite bug: #1588561

Change-Id: I466ebf159e4351f5e2d90cde298531803289ab4d

api-ref/source/v1/stack-events.inc

@@ -94,6 +94,7 @@ Request
    - marker: marker
    - sort_keys: sort_keys
    - sort_dir: sort_dir
+   - nested_depth: nested_depth
 
 
 

releasenotes/notes/event-list-nested-depth-80081a2a8eefee1a.yaml

@@ -0,0 +1,14 @@
+---
+prelude: >
+  Previously the event list REST API call only returned events for the
+  specified stack even when that stack contained nested stack resources. This
+  meant that fetching all nested events required an inefficient recursive
+  client-side implementation.
+features:
+- The event list GET REST API call now has a different behaviour when the
+  'nested_depth' parameter is set to an integer greater than zero. The response
+  will contain all events down to the requested nested depth.
+- When 'nested_depth' is set the response also includes an extra entry in the
+  'links' list with 'rel' set to 'root_stack'. This can be used by client side
+  implementations to detect whether it is necessary to fall back to client-side
+  recurisive event fetching.