Add documentation for Environment Dashboard

Add image of environment dashboard

doc/ci/environments.md

@@ -738,6 +738,11 @@ NOTE: **Note:**
 The most _specific_ spec takes precedence over the other wildcard matching.
 In this case, `review/feature-1` spec takes precedence over `review/*` and `*` specs.
 
+### Environments Dashboard **(PREMIUM)**
+
+See [Environments Dashboard](environments/environments_dashboard.md) for a summary of each
+environment's operational health.
+
 ## Limitations
 
 In the `environment: name`, you are limited to only the [predefined environment variables](variables/predefined_variables.md).

doc/ci/environments/environments_dashboard.md

+---
+type: reference
+---
+
+# Environments Dashboard **(PREMIUM)**
+
+> [Introduced](https://gitlab.com/gitlab-org/gitlab/issues/3713) in [GitLab Premium](https://about.gitlab.com/pricing/) 12.5.
+
+The Environments Dashboard provides a cross-project
+environment-based view that lets you see the big picture
+of what is going on in each environment. From a single
+location, you can track the progress as changes flow
+from development to staging, and then to production (or
+through any series of custom environment flows you can set up).
+With an at-a-glance view of multiple projects, you can instantly
+see which pipelines are green and which are red allowing you to
+diagnose if there is a block at a particular point, or if there’s
+a more systemic problem you need to investigate.
+
+You can access the dashboard from the top bar by clicking
+**More > Environments**.
+
+![Environments Dashboard with projects](img/environments_dashboard_v12_5.png)
+
+The Environments Dashboard displays a maximum of 7 projects
+and 3 environments per project.
+
+The listed environments for each project are unique, such as
+"production", "staging", etc. Review apps and other grouped
+environments are not displayed.
+
+## Adding a project to the dashboard
+
+To add a project to the dashboard:
+
+1. Click the **Add projects** button in the homescreen of the dashboard.
+1. Search and add one or more projects using the **Search your projects** field.
+1. Click the **Add projects** button.
+
+Once added, you can see a summary of each project's environment operational
+health, including the latest commit, pipeline status, and deployment time.
+
+The Environments and [Operations](../../user/operations_dashboard/index.md)
+dashboards share the same list of projects. When you add or remove a
+project from one, GitLab adds or removes the project from the other.
+
+## Environment dashboards on GitLab.com
+
+GitLab.com users can add public projects to the Environments
+Dashboard for free. If your project is private, the group it belongs
+to must have a [GitLab Silver](https://about.gitlab.com/pricing/) plan.

doc/user/operations_dashboard/index.md

@@ -23,6 +23,8 @@ To add a project to the dashboard:
 Once added, the dashboard will display the project's number of active alerts,
 last commit, pipeline status, and when it was last deployed.
 
+The Operations and [Environments](../../ci/environments/environments_dashboard.md) dashboards share the same list of projects. Adding or removing a project from one adds or removes the project from the other.
+
 ![Operations Dashboard with projects](img/index_operations_dashboard_with_projects.png)
 
 ## Arranging projects on a dashboard