Fix Acrolinx validation issues: Add metadata headers and complete lightbox implementation

- Added ms.custom: references_regions to metadata headers for 4 key documentation files
- Removed empty ms.custom fields and build-2025 values as per Acrolinx feedback
- Completed lightbox syntax implementation across all image references
- All images now have proper alt text beginning with 'Screenshot of' and ending with periods
- Improved accessibility and compliance with Azure documentation standards

Author: Mutemwa Masheke

articles/governance/machine-configuration/how-to/assign-security-baselines/specify-custom-parameters-for-baseline-policy.md

@@ -54,7 +54,7 @@ On the **Modify settings** tab, review and adjust configuration rules for your s
 
 - For configurable rules, edit the **Parameter value** field to define your organization's required state.
 
-[![Screenshot of security baseline rules list with checkboxes and parameter value fields.](../../media/specify-custom-parameters-for-baseline-policy/security-baseline-rules-list-with-checkboxes.png)](../../media/specify-custom-parameters-for-baseline-policy/security-baseline-rules-list-with-checkboxes.png#lightbox)
+[![Screenshot of security baseline rules list with checkboxes and parameter value fields.](../../media/specify-custom-parameters-for-baseline-policy/security-baseline-rules-list-with-checked-boxes.png)](../../media/specify-custom-parameters-for-baseline-policy/security-baseline-rules-list-with-checked-boxes.png#lightbox)
 
 - View per rule Metadata by clicking on a highlighted rule. This action opens the context pane showing details such as **Rule ID**, **Description**, **Severity**, and **Compliance Standard**.
 

articles/governance/machine-configuration/overview/01-overview-concepts.md

@@ -96,6 +96,7 @@ Machine configuration built-in policy samples are available in the following loc
 
 ## Next steps
 
+- Discover and assign [built-in policies for Azure Machine Configuration][48]
 - Set up a custom machine configuration package [development environment][33].
 - [Create a package artifact][42] for machine configuration.
 - [Test the package artifact][34] from your development environment.
@@ -151,3 +152,4 @@ Machine configuration built-in policy samples are available in the following loc
 [45]: ../../policy/overview.md
 [46]: /azure/virtual-machine-scale-sets/virtual-machine-scale-sets-orchestration-modes#scale-sets-with-flexible-orchestration
 [47]: ../../policy/concepts/exemption-structure.md
+[48]: ../how-to/assign-built-in-policies.md

articles/governance/machine-configuration/overview/02-setup-prerequisites.md

@@ -110,6 +110,12 @@ properties. An on-demand Azure Policy evaluation retrieves the latest value from
 configuration resource provider. However, it doesn't trigger a new activity within the machine. The
 status is then written to Azure Resource Graph.
 
+## Next steps
+
+Now that you understand the setup prerequisites, continue to the next article to learn about network requirements:
+
+> [Network requirements][28]
+
 
 <!-- Link reference definitions -->
 [09]: /azure/azure-resource-manager/management/resource-providers-and-types#azure-portal
@@ -124,4 +130,5 @@ status is then written to Azure Resource Graph.
 [01]: /azure/azure-arc/servers/overview
 [25]: /azure/active-directory/managed-identities-azure-resources/managed-identities-faq#what-identity-will-imds-default-to-if-dont-specify-the-identity-in-the-request
 [26]: https://portal.azure.com/#blade/Microsoft_Azure_Policy/PolicyDetailBlade/definitionId/%2Fproviders%2FMicrosoft.Authorization%2FpolicyDefinitions%2F3cf2ab00-13f1-4d0c-8971-2ac904541a7e
-[27]: https://portal.azure.com/#blade/Microsoft_Azure_Policy/PolicyDetailBlade/definitionId/%2Fproviders%2FMicrosoft.Authorization%2FpolicyDefinitions%2F497dff13-db2a-4c0f-8603-28fa3b331ab6
+[27]: https://portal.azure.com/#blade/Microsoft_Azure_Policy/PolicyDetailBlade/definitionId/%2Fproviders%2FMicrosoft.Authorization%2FpolicyDefinitions%2F497dff13-db2a-4c0f-8603-28fa3b331ab6
+[28]: ./03-network-requirements.md

articles/governance/machine-configuration/overview/03-network-requirements.md

@@ -113,6 +113,12 @@ When you use [private link with Arc-enabled servers][24], built-in policy packag
 automatically downloaded over the private link. You don't need to set any tags on the Arc-enabled
 server to enable this feature.
 
+## Next steps
+
+Now that you understand the network requirements, continue to the next article to learn about operations and troubleshooting:
+
+[Troubleshooting Machine Configuration][25]
+
 
 <!-- Link reference definitions -->
 [01]: /azure/azure-arc/servers/overview
@@ -123,3 +129,4 @@ server to enable this feature.
 [22]: /azure/virtual-network/what-is-ip-address-168-63-129-16
 [23]: /azure/azure-arc/servers/network-requirements
 [24]: /azure/azure-arc/servers/private-link-security
+[25]: ./04-operations-troubleshooting.md

articles/governance/machine-configuration/overview/04-operations-troubleshooting.md

@@ -158,6 +158,12 @@ packages.
 To provide feedback about this functionality, open an issue on the documentation. We currently
 _don't_ accept PRs for this project, and support is best effort.
 
+## Next steps
+
+Now that you understand operations and troubleshooting, you're ready to start working with machine configuration policies:
+
+[Discover and assign built-in policies for Azure Machine Configuration][48]
+
 
 <!-- Link reference definitions -->
 [28]: /azure/virtual-machines/availability
@@ -171,3 +177,4 @@ _don't_ accept PRs for this project, and support is best effort.
 [36]: /azure/virtual-machines/linux/run-command
 [37]: https://github.com/azure/nxtools#getting-started
 [47]: ../../policy/concepts/exemption-structure.md
+[48]: ../how-to/assign-built-in-policies.md