docs: add missing documentation for cockpit_trigger_test_alert_action (#3528)

Author: jremy42

docs/actions/cockpit_trigger_test_alert_action.md

@@ -0,0 +1,20 @@
+---
+subcategory: "Cockpit"
+page_title: "Scaleway: scaleway_cockpit_trigger_test_alert_action"
+---
+
+# scaleway_cockpit_trigger_test_alert_action (Action)
+
+<!-- action schema generated by tfplugindocs -->
+## Schema
+
+### Required
+
+- `project_id` (String) ID of the Project
+
+### Optional
+
+- `region` (String) The region you want to attach the resource to
+
+
+