format datasources list with columns (#95048)

Co-authored-by: Jack Baldry <jack.baldry@grafana.com>

docs/sources/datasources/_index.md

@@ -138,6 +138,8 @@ A data source that uses the result set from another panel in the same dashboard.
 
 These built-in core data sources are also included in the Grafana documentation:
 
+{{< column-list >}}
+
 - [Alertmanager]({{< relref "./alertmanager" >}})
 - [AWS CloudWatch]({{< relref "./aws-cloudwatch" >}})
 - [Azure Monitor]({{< relref "./azure-monitor" >}})
@@ -157,6 +159,8 @@ These built-in core data sources are also included in the Grafana documentation:
 - [Testdata]({{< relref "./testdata" >}})
 - [Zipkin]({{< relref "./zipkin" >}})
 
+{{< /column-list >}}
+
 ## Add additional data source plugins
 
 You can add additional data sources as plugins (that are not available in core Grafana), which you can install or create yourself.