Revisions for tone and style

Revises the Incident List section to get closer to GitLab tone
and style. Puts the list of explanatory items under the image.

doc/operations/incident_management/index.md

@@ -366,6 +366,22 @@ These emails contain details of the alert, and a link for more information.
 To send separate email notifications to users with
 [Developer permissions](../../user/permissions.md), see [Configure incidents](#configure-incidents).
 
+## Incident List
+
+Incidents in GitLab are aggregated in the Incident List, available at
+**Operations > Incidents**. This list displays all incidents in GitLab, with tabs
+to display open incidents, closed incidents, and all incidents:
+
+![Incident list](img/incident_list.png)
+
+The list displays the following attributes:
+
+- **Incident title**
+- **Date created** - in 'time ago' format.
+- **Assignees** - the avatar of the user assigned to the incident.
+- **Published** - Displays a green check mark (**{check-circle}**) if the incident is published
+  to a [Status Page](status_page.md).
+
 ## Create an incident manually
 
 > [Moved](https://gitlab.com/gitlab-org/monitor/health/-/issues/24) to GitLab core in 13.3.