Add documentation for Merge Request Analytics

The recently-introduced Merge Request Analytics feature did not have
any documentation yet, so this adds a page.

doc/README.md

@@ -157,6 +157,7 @@ The following documentation relates to the DevOps **Create** stage:
 | [GitLab Pages](user/project/pages/index.md)                                                                                                                                                      | Build, test, and deploy your static website with GitLab Pages.                                   |
 | [Groups](user/group/index.md) and [Subgroups](user/group/subgroups/index.md)                                                                                                                     | Organize your projects in groups.                                                                |
 | [Issues Analytics](user/group/issues_analytics/index.md) **(PREMIUM)**                                                                                                                           | Check how many issues were created per month.                                                    |
+| [Merge Request Analytics](user/analytics/merge_request_analytics.md) **(PREMIUM)**                                                                                                                           | Check your throughput productivity - how many merge requests were merged per month.                                                    |
 | [Projects](user/project/index.md), including [project access](public_access/public_access.md)<br/>and [settings](user/project/settings/index.md)                                                 | Host source code, and control your project's visibility and set configuration.                   |
 | [Search through GitLab](user/search/index.md)                                                                                                                                                    | Search for issues, merge requests, projects, groups, and todos.                                  |
 | [Snippets](user/snippets.md)                                                                                                                                                                     | Snippets allow you to create little bits of code.                                                |

doc/user/analytics/index.md

@@ -38,6 +38,7 @@ The following analytics features are available at the project level:
 - [Code Review](code_review_analytics.md). **(STARTER)**
 - [Insights](../group/insights/index.md). **(ULTIMATE)**
 - [Issues](../group/issues_analytics/index.md). **(PREMIUM)**
+- [Merge Request](merge_request_analytics.md). **(STARTER)**
 - [Repository](repository_analytics.md).
 - [Value Stream](value_stream_analytics.md), enabled with the `cycle_analytics`
   [feature flag](../../development/feature_flags/development.md#enabling-a-feature-flag-locally-in-development). **(STARTER)**

doc/user/analytics/merge_request_analytics.md

+---
+description: "Merge Request Analytics help you understand the efficiency of your code review process, and the productivity of your team." # Up to ~200 chars long. They will be displayed in Google Search snippets. It may help to write the page intro first, and then reuse it here.
+stage: Manage
+group: Analytics
+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/#designated-technical-writers
+---
+
+
+# Merge Request Analytics **(STARTER)**
+
+> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/229045) in [GitLab Starter](https://about.gitlab.com/pricing/) 13.3.
+
+Merge Request Analytics helps you understand the efficiency of your code review process, and the productivity of your team.
+
+## Overview
+
+Merge Request Analytics displays information about all accepted merge requests.
+
+The Throughput chart shows the number of completed merge requests, by month. Merge request throughput is
+a common measure of productivity in software engineering. Although imperfect, the average throughput can
+be a meaningful benchmark of your team's overall productivity.
+
+To access Merge Request Analytics, from your project's menu, go to **Analytics > Merge Request**.
+
+![Merge Request Analytics](img/merge_request_analytics_v13_3.png "Merge Request Analytics - Throughput chart")
+
+## Use cases
+
+This feature is designed for [development team leaders](https://about.gitlab.com/handbook/marketing/product-marketing/roles-personas/#delaney-development-team-lead)
+and others who want to understand broad patterns in code review and productivity.
+
+You can use Merge Request Analytics to expose when your team is most and least productive, and
+identify improvements that might substantially accelerate your development cycle.
+
+Merge Request Analytics could be used when:
+
+- You want to know if you were more productive this month than last month, or 12 months ago.
+- You want to drill into low- or high-productivity months to understand the work that took place.
+
+## Permissions
+
+- On [Starter or Bronze tier](https://about.gitlab.com/pricing/) and above.

doc/user/permissions.md

@@ -168,6 +168,7 @@ The following table depicts the various user permission levels in a project.
 | View Code Review analytics **(STARTER)**          |         | ✓          | ✓           | ✓        | ✓      |
 | View Insights **(ULTIMATE)**                      | ✓       | ✓          | ✓           | ✓        | ✓      |
 | View Issues analytics **(PREMIUM)**               | ✓       | ✓          | ✓           | ✓        | ✓      |
+| View Merge Request analytics **(STARTER)**        | ✓       | ✓          | ✓           | ✓        | ✓      |
 | View Repository analytics                         |         | ✓          | ✓           | ✓        | ✓      |
 | View Value Stream analytics                       | ✓       | ✓          | ✓           | ✓        | ✓      |