Add first cut of Status page docs

- Setup
- detail page
- publishing incidents
- Publishing updated
- Adding comments
- Incident status

doc/user/project/status_page/index.md

+# GitLab Status Page
+
+> [Introduced](https://gitlab.com/groups/gitlab-org/-/epics/2479) in GitLab 12.10.
+
+GitLab Status Page allows you to create and deploy a static website to communicate efficiently to users during an incident.
+
+## How to set up
+
+NOTE: **Note:**
+Only AWS S3 is supported as a deploy target.
+
+```mermaid
+graph TB
+    subgraph GitLab Instance
+    issues(issue updates) -- trigger --> middleware(Background job: JSON generation)
+    end
+    subgraph Cloud Provider
+    middleware --saves data --> c1(Cloud Bucket stores JSON file)
+    end
+    subgraph Status Page
+    d(Static Site on CDN) -- fetches data --> c1
+    end
+```
+
+Setting up a Status Page is pretty painless but there are a few things you need to do.
+
+### Cloud account set up
+
+To use GitLab Status Page you first need to set up your account details for your cloud provider in the operations settings page. Today, only AWS is supported.
+
+1. Within your AWS account, create an AWS access key.
+1. Add the following permissions policies:
+    - [Create bucket](https://gitlab.com/gitlab-org/status-page/-/blob/master/deploy/etc/s3_create_policy.json).
+    - [Update bucket contents](https://gitlab.com/gitlab-org/status-page/-/blob/master/deploy/etc/s3_update_bucket_policy.json) (Remember replace `S3_BUCKET_NAME` with your bucket name).
+
+### Status Page project
+
+To deploy the status page to AWS S3 you need to add the Status Page project & configure the necessary CI variables.
+
+1. Fork the [Status Page](https://gitlab.com/gitlab-org/status-page) project. This can also be done via [Repository Mirroring](https://gitlab.com/gitlab-org/status-page#repository-mirroring) which will ensure you get the up-to-date Status Page features.
+1. Add the following variables in **Settings > CI/CD > Variables**. (To get these variables from Amazon, use your Amazon Console):
+    - `S3_BUCKET_NAME` - name of the Amazon S3 bucket
+    - `AWS_DEFAULT_REGION` - the AWS region
+    - `AWS_ACCESS_KEY_ID` - the AWS access key ID
+    - `AWS_SECRET_ACCESS_KEY` - the AWS secret
+1. Run the pipeline to deploy the status page to S3.
+
+### Syncing incidents to the Status Page
+
+Once the CI/CD variables are set, you'll need to set up the Project you want to use for Incident issues:
+
+1. Navigate to **Settings > Operations > Status Page**.
+1. Fill in your cloud provider's credentials and make sure the **Active** checkbox is checked.
+1. Click **Save changes**.
+
+## Status Page UI
+
+The Status page landing page shows you an overview of the recent incidents. Clicking on an incident will take you to the incident's detail page.
+
+![Status Page landing page](../img/status_page_incidents_v12_10.png)
+
+### Incident detail page
+
+The incident detail page shows detailed information about a particular incident. For example:
+
+- Status on the incident, including when the incident was last updated.
+- The incident title.
+- The description of the incident.
+- A chronological ordered list of updates to the incident.
+
+![Status Page detail](../img/status_page_detail_v12_10.png)
+
+## How it works
+
+### Publishing Incidents
+
+To publish an Incident, you first need to create an issue in the Project you enabled the Status Page settings in.
+
+Once this issue is created, a background worker will publish the issue onto the status page using the credentials you provided during setup.
+
+### Publishing updates
+
+To publish an update to the Incident, update the incident issue's description.
+
+### Adding comments
+
+To add comments to the Status Page Incident, create a comment on the incident issue.
+
+When you're ready to publish the comment, add a microphone [award emoji](../../../user/award_emojis.md) reaction (`:microphone` 🎤) to the comment. This marks the comment as one which should be deployed to the Status Page.
+
+CAUTION: **Caution:**
+Anyone with access to view the Issue can add an Emoji Award to a comment, so you may want to keep your Issues limited to team members only.
+
+### Changing the Incident status
+
+To change the incident status from `open` to `closed`, close the incident issue within GitLab. This will then be updated shortly on the Status page website.