adds sigma as SL integration (#6670)

this PR adds sigma as an SL integration (available in preview)

[ ] needs pm review
[ ] needs docs review (optional)

<!-- vercel-deployment-preview -->
---
🚀 Deployment available! Here are the direct links to the updated files:


-
https://docs-getdbt-com-git-sl-sigma-preview-dbt-labs.vercel.app/docs/dbt-versions/release-notes

<!-- end-vercel-deployment-preview -->

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Co-authored-by: Leona B. Campbell <3880403+runleonarun@users.noreply.github.com>

website/docs/docs/dbt-versions/release-notes.md

@@ -20,6 +20,7 @@ Release notes are grouped by month for both multi-tenant and virtual private clo
 
 ## December 2024
 
+- **New**: The dbt Semantic Layer supports Sigma as a [partner integration](/docs/cloud-integrations/avail-sl-integrations), available in Preview. Refer to [Sigma](https://help.sigmacomputing.com/docs/configure-a-dbt-semantic-layer-integration) for more information.
 - **New**: The dbt Semantic Layer now supports Azure Single-tenant deployments. Refer to [Set up the dbt Semantic Layer](/docs/use-dbt-semantic-layer/setup-sl) for more information on how to get started.
 - **Fix**: Resolved intermittent issues in Single-tenant environments affecting Semantic Layer and query history.
 - **Fix**: [The dbt Semantic Layer](/docs/use-dbt-semantic-layer/dbt-sl) now respects the BigQuery [`execution_project` attribute](/docs/core/connect-data-platform/bigquery-setup#execution-project), including for exports.

website/snippets/_sl-partner-links.md

@@ -106,6 +106,21 @@ The following tools integrate with the dbt Semantic Layer:
     </a>
 </div>
 
+<div className="card-container">
+  <Card
+    title="Sigma (Preview)"
+    body="Connect Sigma to the dbt Semantic Layer to allow you to leverage your predefined dbt metrics in Sigma workbooks."
+    link="https://help.sigmacomputing.com/docs/configure-a-dbt-semantic-layer-integration"
+    icon="sigma"/>
+    <a href="https://help.sigmacomputing.com/docs/configure-a-dbt-semantic-layer-integration"
+    className="external-link"
+      target="_blank"
+      rel="noopener noreferrer">
+      <Icon name='fa-external-link' />
+    </a>
+</div>
+
+
 <div className="card-container">
   <Card
     title="Steep"