[8.6] Changes 'in-progress' to 'acknowledged' (#2811) (#2812)

* Changes 'in-progress' to 'acknowledged'

* Update docs/detections/api/rules/signals-api-overview.asciidoc

Co-authored-by: Joe Peeples <joe.peeples@elastic.co>

Co-authored-by: Joe Peeples <joe.peeples@elastic.co>
(cherry picked from commit 2aaa334)

Co-authored-by: Benjamin Ironside Goldstein <91905639+benironside@users.noreply.github.com>

docs/detections/api/rules/signals-api-overview.asciidoc

@@ -159,7 +159,7 @@ not used.
 |`query` |Query DSL |Query that determines which alerts are updated. |Yes, when
 the `signal_ids` field is not used.
 
-|`status` |String |The new status, which can be `open`, `in-progress` or
+|`status` |String |The new status, which can be `open`, `acknowledged`, or
 `closed`. |Yes.
 
 |==============================================