Add documentation for deployment frequency graphs

This commit updates the documentation to include an explanation of how
to use the deployment frequency graphs on the CI / CD Analytics page.

doc/ci/pipelines/index.md

@@ -349,18 +349,7 @@ Stages in pipeline mini graphs are collapsible. Hover your mouse over them and c
 
 ### Pipeline success and duration charts
 
-> - Introduced in GitLab 3.1.1 as Commit Stats, and later renamed to Pipeline Charts.
-> - [Renamed](https://gitlab.com/gitlab-org/gitlab/-/issues/38318) to CI / CD Analytics in GitLab 12.8.
-
-GitLab tracks the history of your pipeline successes and failures, as well as how long each pipeline ran. To view this information, go to **Analytics > CI / CD Analytics**.
-
-View successful pipelines:
-
-![Successful pipelines](img/pipelines_success_chart.png)
-
-View pipeline duration history:
-
-![Pipeline duration](img/pipelines_duration_chart.png)
+Pipeline analytics are available on the [**CI/CD Analytics** page](../../user/analytics/ci_cd_analytics.md#pipeline-success-and-duration-charts).
 
 ### Pipeline badges
 

doc/user/analytics/ci_cd_analytics.md

+---
+stage: Release
+group: Release
+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
+---
+
+# CI/CD Analytics
+
+## Pipeline success and duration charts **(CORE)**
+
+> - Introduced in GitLab 3.1.1 as Commit Stats, and later renamed to Pipeline Charts.
+> - [Renamed](https://gitlab.com/gitlab-org/gitlab/-/issues/38318) to CI/CD Analytics in GitLab 12.8.
+
+GitLab tracks the history of your pipeline successes and failures, as well as how long each pipeline
+ran. To view this information, go to **Analytics > CI/CD Analytics**.
+
+View successful pipelines:
+
+![Successful pipelines](img/pipelines_success_chart.png)
+
+View pipeline duration history:
+
+![Pipeline duration](img/pipelines_duration_chart.png)
+
+## Deployment frequency charts **(ULTIMATE)**
+
+> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/275991) in GitLab 13.8.
+
+The **Analytics > CI/CD Analytics** page shows information about the deployment frequency to the
+`production` environment. The environment **must** be named `production` for its deployment
+information to appear on the graphs.
+
+![Deployment frequency](img/deployment_frequency_chart_v13_8.png)

doc/user/analytics/index.md

@@ -33,7 +33,7 @@ The following analytics features are available at the group level:
 
 The following analytics features are available at the project level:
 
-- [CI/CD](../../ci/pipelines/index.md#pipeline-success-and-duration-charts). **(STARTER)**
+- [CI/CD](ci_cd_analytics.md). **(CORE)**
 - [Code Review](code_review_analytics.md). **(STARTER)**
 - [Insights](../project/insights/index.md). **(ULTIMATE)**
 - [Issue](../group/issues_analytics/index.md). **(PREMIUM)**