[March 24] Security overview beta (#18341)

* Add 'Security Center' product name variable

* Update index with new Security Center category

* Revert "Update index with new Security Center category"

This reverts commit 74aee4b050639626d2b49d914e4ab7b8c0f63ddc.

* Update Code Security index

* Create index.md for Security Center

* Create Security Center reusables

Beta flag and gated feature

* update AE versioning

* Remove "Security Center" from titles and intros

* Remove "security center" from beta flag

* Add images

* Procedures for filtering and sorting

* Incorporate reviewer feedback

* Incorporate reviewer feedback

Three images will need to be updated

* Update images

data/reusables/gated-features/security-center.md

@@ -0,0 +1,4 @@
+{% if currentVersion == "github-ae@latest" %}
+The security overview for your organization is available if you have a license for {% data variables.product.prodname_GH_advanced_security %}, which is free during the beta release.
+{% else %}
+The security overview for your organization is available if you have a license for {% data variables.product.prodname_GH_advanced_security %}.{% endif %} {% data reusables.advanced-security.more-info-ghas %}

data/reusables/organizations/filter-security-overview.md

@@ -0,0 +1,2 @@
+1. Optionally, filter the list of alerts. You can click multiple filters in the drop-down filter menus to narrow your search. You can also type search qualifiers in the **Search repositories** field. For more information about the available qualifiers, see "[Filtering the list of alerts](#filtering-the-list-of-alerts)."
+  ![The drop-down filter menus and Search repositories field in the security overview](/assets/images/help/organizations/security-overview-filter-alerts.png)

data/reusables/organizations/security-overview.md

@@ -0,0 +1,2 @@
+1. Under your organization name, click {% octicon "shield" aria-label="The Security shield" %} **Security**.
+![Organization security button](/assets/images/help/organizations/organization-security-tab.png)

data/reusables/organizations/team-security-overview.md

@@ -0,0 +1,2 @@
+1. At the top of the team's page, click {% octicon "shield" aria-label="The security icon" %} **Security**.
+  ![Team security overview](/assets/images/help/teams/org-team-page-security-overview.png)

data/reusables/security-center/beta.md

@@ -0,0 +1,5 @@
+{% note %}
+
+**Note:** The security overview is currently in beta and subject to change.
+
+{% endnote %}

data/variables/product.yml

@@ -114,6 +114,9 @@ prodname_matching_fund: 'GitHub Sponsors Matching Fund'
 prodname_GH_advanced_security: 'GitHub Advanced Security'
 prodname_advanced_security: 'Advanced Security'
 
+# Security Center
+prodname_security_center: 'Security Center'
+
 # Codespaces
 prodname_codespaces: 'Codespaces'
 prodname_vs_codespaces: 'Visual Studio Codespaces'