Docs(oncallschedules): add On-call schedule documentation

Add the base documentation
for On-call schedules to the
GitLab code base

doc/operations/incident_management/oncall_schedules.md

+---
+stage: Monitor
+group: Monitor
+info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
+---
+
+# On-call Schedule Management **(PREMIUM)**
+
+> [Introduced](https://gitlab.com/groups/gitlab-org/-/epics/4544) in [GitLab Premium](https://about.gitlab.com/pricing/) 13.10.
+
+Use on-call schedule management to create schedules for responders to rotate on-call
+responsibilities. Maintain the availability of your software services by putting your teams on-call.
+With an on-call schedule, your team is notified immediately when things go wrong so they can quickly
+respond to service outages and disruptions.
+
+To use on-call schedules, you must do the following:
+
+1. [Create a schedule](#schedules).
+1. [Add a rotation to the schedule](#rotations).
+
+If you have at least Maintainer [permissions](../../user/permissions.md)
+to create a schedule, you can do this manually.
+
+## Schedules
+
+Set up an on-call schedule for your team to add rotations to.
+
+Follow these steps to create a schedule:
+
+1. Go to **Operations > On-call Schedules** and select **Add a schedule**.
+1. In the **Add schedule** form, enter the schedule's name and description, and select a timezone.
+1. Click **Add schedule**.
+
+You now have an empty schedule with no rotations. This renders as an empty state, prompting you to
+create [rotations](#rotations) for your schedule.
+
+![Schedule Empty Grid](img/oncall_schedule_empty_grid_v13_10.png)
+
+### Update a schedule
+
+Follow these steps to update a schedule:
+
+1. Go to **Operations > On-call Schedules** and select the **Pencil** icon on the top right of the
+   schedule card, across from the schedule name.
+1. In the **Edit schedule** form, edit the information you wish to update.
+1. Click the **Edit schedule** button to save your changes.
+
+### Delete a schedule
+
+Follow these steps to delete a schedule:
+
+1. Go to **Operations > On-call Schedules** and select the **Trash Can** icon on the top right of the
+   schedule card.
+1. In the **Delete schedule** window, click the **Delete schedule** button.
+
+## Rotations
+
+Add rotations to an existing schedule to put your team members on-call.
+
+Follow these steps to create a rotation:
+
+1. Go to **Operations > On-call Schedules** and select **Add a rotation** on the top right of the
+   current schedule.
+1. In the **Add rotation** form, enter the following:
+
+   - **Name:** Your rotation's name.
+   - **Participants:** The people you want in the rotation.
+   - **Rotation length:** The rotation's duration.
+   - **Starts on:** The date and time the rotation begins.
+   - **Enable end date:** With the toggle set to on, you can select the date and time your rotation
+     ends.
+   - **Restrict to time intervals:** With the toggle set to on, you can restrict your rotation to
+     the time period you select.
+
+### Edit a rotation
+
+Follow these steps to edit a rotation:
+
+1. Go to **Operations > On-call Schedules** and select the **Pencil** icon to the right of the title
+   of the rotation that you want to update.
+1. In the **Edit rotation** form, make the changes that you want.
+1. Select the **Edit rotation** button.
+
+### Delete a rotation
+
+Follow these steps to delete a rotation:
+
+1. Go to **Operations > On-call Schedules** and select the **Trash Can** icon to the right of the
+   title of the rotation that you want to delete.
+1. In the **Delete rotation** window, select the **Delete rotation** button.
+
+## View schedule rotations
+
+You can view the on-call schedules of a single day or two weeks. To switch between these time
+periods, select the **1 day** or **2 weeks** buttons on the schedule. Two weeks is the default view.
+
+Hover over any rotation shift participants in the schedule to view their individual shift details.
+
+![1 Day Grid View](img/oncall_schedule_day_grid_v13_10.png)
+
+## Page an on-call responder
+
+When an alert is created in a project, GitLab sends an email to the on-call responder(s) in the
+on-call schedule for that project. If there is no schedule or no one on-call in that schedule at the
+time the alert is triggered, no email is sent.

doc/operations/incident_management/paging.md

@@ -32,3 +32,9 @@ a single email notification for new alerts.
 1. In the **Alert Integration** tab, select the checkbox
    **Send a single email notification to Owners and Maintainers for new alerts**.
 1. Select **Save changes**.
+
+## Paging **(PREMIUM)**
+
+In projects that have an [on-call schedule](oncall_schedules.md) configured, on-call responders are
+paged through email for triggered alerts. The on-call responder(s) receive one email for triggered
+alerts.