Document adding an application limit to Environment Dashboard

Part of https://gitlab.com/gitlab-org/gitlab/-/issues/33895

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/40703

doc/administration/instance_limits.md

@@ -424,6 +424,12 @@ panel_groups:
       label: Legend Label
 ```
 
+## Environment Dashboard limits **(PREMIUM)**
+
+> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/33895) in GitLab 13.4.
+
+The [Environment Dashboard](../ci/environments/environments_dashboard.md) supports the addition of a maximum of 150 projects.
+
 ## Environment data on Deploy Boards
 
 [Deploy Boards](../user/project/deploy_boards.md) load information from Kubernetes about

doc/ci/environments/environments_dashboard.md

@@ -25,8 +25,8 @@ You can access the dashboard from the top bar by clicking
 
 ![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 Environments Dashboard offers a paginated display of a maximum of 
+150 projects and 3 environments per project.
 
 The listed environments for each project are unique, such as
 "production", "staging", etc. Review apps and other grouped
@@ -47,6 +47,8 @@ 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.
 
+A maximum of 150 projects may be added.
+
 ## Environment dashboards on GitLab.com
 
 GitLab.com users can add public projects to the Environments