Update docs for CE Security Configuration page

Part of https://gitlab.com/gitlab-org/gitlab/-/issues/294076.

doc/user/application_security/configuration/index.md

@@ -5,14 +5,22 @@ group: Static Analysis
 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
 ---
 
-# Security Configuration **(ULTIMATE)**
+# Security Configuration **(FREE)**
 
-> - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/20711) in [GitLab Ultimate](https://about.gitlab.com/pricing/) 12.6.
-> - SAST configuration was [enabled](https://gitlab.com/groups/gitlab-org/-/epics/3659) in 13.3 and [improved](https://gitlab.com/gitlab-org/gitlab/-/issues/232862) in 13.4.
-> - DAST Profiles feature was [introduced](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/40474) in 13.4.
+> - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/20711) in [GitLab Ultimate](https://about.gitlab.com/pricing/) 12.6. **(ULTIMATE)**
+> - SAST configuration was [enabled](https://gitlab.com/groups/gitlab-org/-/epics/3659) in 13.3 and [improved](https://gitlab.com/gitlab-org/gitlab/-/issues/232862) in 13.4. **(ULTIMATE)**
+> - DAST Profiles feature was [introduced](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/40474) in 13.4. **(ULTIMATE)**
+> - A simplified version was made [available in all tiers](https://gitlab.com/gitlab-org/gitlab/-/issues/294076) in GitLab 13.9. **(FREE)**
+> - It's [deployed behind a feature flag](../../feature_flags.md), disabled by default.
+> - It's enabled on GitLab.com.
+> - It's recommended for production use.
+> - For GitLab self-managed instances, GitLab administrators can opt to [enable it](#enable-or-disable-security-configuration). **(FREE SELF)**
+> - It can be enabled or disabled for a single project.
+
+WARNING:
+This feature might not be available to you. Check the **version history** note above for details.
 
-The Security Configuration page displays the configuration state of each security control in the
-current project.
+The Security Configuration page displays what security scans are available, links to documentation and also simple enablement tools for the current project.
 
 To view a project's security configuration, go to the project's home page,
 then in the left sidebar go to **Security & Compliance > Configuration**.
@@ -20,10 +28,11 @@ then in the left sidebar go to **Security & Compliance > Configuration**.
 For each security control the page displays:
 
 - **Security Control:** Name, description, and a documentation link.
-- **Status:** The security control's status (enabled, not enabled, or available).
 - **Manage:** A management option or a documentation link.
 
-## Status
+## Status **(ULTIMATE)**
+
+> - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/20711) in [GitLab Ultimate](https://about.gitlab.com/pricing/) 12.6.
 
 The status of each security control is determined by the project's latest default branch
 [CI pipeline](../../../ci/pipelines/index.md).
@@ -35,7 +44,7 @@ all security features are configured by default.
 
 For SAST, click **View history** to see the `.gitlab-ci.yml` file's history.
 
-## Manage
+## Manage **(ULTIMATE)**
 
 You can configure the following security controls:
 
@@ -45,3 +54,25 @@ You can configure the following security controls:
   - Click either **Enable** or **Configure** to use SAST for the current project. For more details, see [Configure SAST in the UI](../sast/index.md#configure-sast-in-the-ui).
 - DAST Profiles
   - Click **Manage** to manage the available DAST profiles used for on-demand scans. For more details, see [DAST on-demand scans](../dast/index.md#on-demand-scans).
+
+### Enable or disable Security Configuration **(FREE SELF)**
+
+Security Configuration is under development but ready for production use.
+It is deployed behind a feature flag that is **disabled by default**.
+[GitLab administrators with access to the GitLab Rails console](../../../administration/feature_flags.md)
+can opt to enable it.
+
+NOTE:
+This does not apply to GitLab Ultimate.
+
+To enable it:
+
+```ruby
+Feature.enable(:secure_security_and_compliance_configuration_page_on_ce, Project.find(<project id>))
+```
+
+To disable it:
+
+```ruby
+Feature.disable(:secure_security_and_compliance_configuration_page_on_ce, Project.find(<project id>))
+```