Improve MR Analytics documentation

This adds information about the MR Analytics features, permissions,
and feature flag to make this documentation more useful for users.

doc/user/analytics/index.md

@@ -38,7 +38,8 @@ The following analytics features are available at the project level:
 - [Code Review](code_review_analytics.md). **(STARTER)**
 - [Insights](../group/insights/index.md). **(ULTIMATE)**
 - [Issue](../group/issues_analytics/index.md). **(PREMIUM)**
-- [Merge Request](merge_request_analytics.md). **(STARTER)**
+- [Merge Request](merge_request_analytics.md), enabled with the `project_merge_request_analytics`
+  [feature flag](../../development/feature_flags/development.md#enabling-a-feature-flag-locally-in-development). **(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

@@ -5,7 +5,6 @@ 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.
@@ -14,7 +13,7 @@ Merge Request Analytics helps you understand the efficiency of your code review
 
 ## Overview
 
-Merge Request Analytics displays information about all accepted merge requests.
+Merge Request Analytics displays information that will help you evaluate the efficiency and productivity of your merge request process.
 
 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
@@ -22,8 +21,6 @@ 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)
@@ -37,6 +34,40 @@ 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.
 
+## Visualizations and data
+
+The following visualizations and data are available, representing all merge requests that were merged in the past 12 months.
+
+### Throughput chart
+
+The throughput chart shows the number of completed merge requests per month.
+
+![Throughput chart](img/mr_throughput_chart_v13_3.png "Merge Request Analytics - Throughput chart showing merge requests merged in the past 12 months")
+
+### Throughput table
+
+Data table displaying a maximum of the 100 most recent merge requests merged for the time period.
+
+![Throughput table](img/mr_throughput_table_v13_3.png "Merge Request Analytics - Throughput table listing the 100 merge requests most recently merged")
+
 ## Permissions
 
-- On [Starter or Bronze tier](https://about.gitlab.com/pricing/) and above.
+The **Merge Request Analytics** feature can be accessed only:
+
+- On [Starter](https://about.gitlab.com/pricing/) and above.
+- By users with [Reporter access](../permissions.md) and above.
+
+## Enable and disable related feature flags
+
+Merge Request Analytics is disabled by default but can be enabled using the following
+[feature flag](../../development/feature_flags/development.md#enabling-a-feature-flag-locally-in-development):
+
+- `project_merge_request_analytics`
+
+A GitLab administrator can:
+
+- Enable this feature by running the following command in a Rails console:
+
+  ```ruby
+  Feature.enable(:project_merge_request_analytics)
+  ```