dhi: add cis compliance concept (#23237)

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## Description

Added CIS Docker concept.
Updated index for the concepts.


https://deploy-preview-23237--docsdocker.netlify.app/dhi/core-concepts/cis/

https://deploy-preview-23237--docsdocker.netlify.app/dhi/core-concepts/#compliance-standards

## Related issues or tickets

DHI-620

## Reviews

<!-- Notes for reviewers here -->
<!-- List applicable reviews (optionally @tag reviewers) -->

- [ ] Editorial review
- [ ] Product review

Signed-off-by: Craig <[email protected]>

Author: craig-osterhout

content/manuals/dhi/core-concepts/_index.md

@@ -20,6 +20,8 @@ params:
       description: Learn how build provenance metadata helps trace the origin of Docker Hardened Images and support compliance with SLSA.
       icon: track_changes
       link: /dhi/core-concepts/provenance/
+
+  grid_concepts_compliance:
     - title: FIPS
       description: Learn how Docker Hardened Images support FIPS 140 by using validated cryptographic modules and providing signed attestations for compliance audits.
       icon: verified
@@ -28,6 +30,10 @@ params:
       description: Learn how Docker Hardened Images provide STIG-hardened container images with verifiable security scan attestations for government and enterprise compliance requirements.
       icon: policy
       link: /dhi/core-concepts/stig/
+    - title: CIS Benchmarks
+      description: Learn how Docker Hardened Images help you meet Center for Internet Security (CIS) Docker Benchmark requirements for secure container configuration and deployment.
+      icon: check_circle
+      link: /dhi/core-concepts/cis/
 
   grid_concepts_risk:
     - title: Common Vulnerabilities and Exposures (CVEs)
@@ -84,10 +90,15 @@ and VEX.
 Start here if you want to understand how Docker Hardened Images support compliance,
 transparency, and security.
 
+
 ## Security metadata and attestations
 
 {{< grid items="grid_concepts_metadata" >}}
 
+## Compliance standards
+
+{{< grid items="grid_concepts_compliance" >}}
+
 ## Vulnerability and risk management
 
 {{< grid items="grid_concepts_risk" >}}

content/manuals/dhi/core-concepts/cis.md

@@ -0,0 +1,53 @@
+---
+title: CIS Benchmark
+description: Learn how Docker Hardened Images comply with the CIS Docker Benchmark to help organizations harden container images for secure deployments.
+keywords: docker cis benchmark, cis docker compliance, cis docker images, docker hardened images, secure container images
+---
+
+## What is the CIS Docker Benchmark?
+
+The [CIS Docker Benchmark](https://www.cisecurity.org/benchmark/docker) is part
+of the globally recognized CIS Benchmarks, developed by the [Center for
+Internet Security (CIS)](https://www.cisecurity.org/). It defines recommended secure
+configurations for all aspects of the Docker container ecosystem, including the
+container host, Docker daemon, container images, and the container runtime.
+
+## Why CIS Benchmark compliance matters
+
+Following the CIS Docker Benchmark helps organizations:
+
+- Reduce security risk with widely recognized hardening guidance.
+- Meet regulatory or contractual requirements that reference CIS controls.
+- Standardize image and Dockerfile practices across teams.
+- Demonstrate audit readiness with configuration decisions grounded in a public standard.
+
+## How Docker Hardened Images comply with the CIS Benchmark
+
+Docker Hardened Images (DHIs) are designed with security in mind and are
+verified to be compliant with the relevant controls from the latest CIS
+Docker Benchmark (v1.8.0) for the scope that applies to container images and
+Dockerfile configuration.
+
+CIS-compliant DHIs are compliant with all controls in Section 4, with the sole
+exception of the control requiring Docker Content Trust (DCT), which [Docker
+officially retired](https://www.docker.com/blog/retiring-docker-content-trust/).
+By starting from a CIS-compliant DHI, teams can adopt image-level best practices
+from the benchmark more quickly and confidently.
+
+> [!NOTE]
+>
+> The CIS Docker Benchmark also includes controls for the host, daemon, and
+> runtime. CIS-compliant DHIs address only the image and Dockerfile scope (Section
+> 4). Overall compliance still depends on how you configure and operate the
+> broader environment.
+
+## Identify CIS-compliant images
+
+CIS-compliant images are labeled as **CIS** in the Docker Hardened Images catalog.
+To find them, [explore images](../how-to/explore.md) and look for the **CIS**
+designation on individual listings.
+
+## Get the benchmark
+
+Download the latest CIS Docker Benchmark directly from CIS:
+https://www.cisecurity.org/benchmark/docker