CIE-5505 - Having DataHub Edge doc in a single place (#3944)

Somebody complained (reasonably) that the documentation for DataHub on Edge was slightly fragmented, and would sometimes send you on a link wild goose chase between the DataHub and Edge sections of the doc.

I've transplanted everything into the Edge section of the doc. I think this makes more sense now that Edge is just a Kubernetes-based mini-cloud, and DataHub is "just" another component (with some caveats).

For the same reasons, I've removed a bunch of the kubernetes diagnostic content, because Edge health checks all of its components, and aggregates all of its logs.

Author: rthrippleton

.github/CODEOWNERS

@@ -22,7 +22,6 @@ content/authentication @kowa-c8y @BeateRixen
 # Edge
 /content/edge* @bbyreddy @rthrippleton @BeateRixen
 /static/files/edge* @bbyreddy @rthrippleton @BeateRixen
-/content/datahub/running-datahub-on-the-edge* @bbyreddy @rthrippleton @BeateRixen
 
 /content/streaming-analytics/ @BeateRixen @skom-c8y
 # 'block-reference-bundle' is automatically and frequently committed to - don't bother _too many_ CODEOWNERS

content/change-logs/edge/edge-2025.0.0-datahub.md

@@ -16,4 +16,4 @@ version: 2025.0.0
 ---
 {{< product-c8y-iot >}} Edge now supports installing and upgrading the {{< product-c8y-iot >}} DataHub Edge using the Edge operator.
 
-For more details, see [Setting up DataHub Edge](/datahub/running-datahub-on-the-edge/#setting-up-datahub-edge).
+For more details, see [DataHub](/edge-kubernetes/datahub).

content/change-logs/edge/edge-2025.0.8-CIE-5487.md

@@ -16,7 +16,7 @@ version: 2025.0.8
 ---
 In previous versions of {{< product-c8y-iot >}} Edge, a race condition caused the Dremio component of DataHub to start up without authentication being configured, breaking almost all aspects of DataHub. This issue has now been fixed.
 
-If you have a system that is suffering from this problem but otherwise functional, you do not need to do a fresh installation of Edge. Instead, disable DataHub in your current Edge installation, and then upgrade to the latest version of Edge. After the upgrade, re-enable DataHub, and the problem will be cleared up. See [Upgrading Edge](/edge-kubernetes/manage-edge/#version-upgrade) for instructions on upgrading. For disabling and enabling DataHub, see [More general configuration changes](edge-kubernetes/manage-edge/#more-general-configuration-changes). The value you will be changing in the Custom Resource looks like this:
+If you have a system that is suffering from this problem but otherwise functional, you do not need to do a fresh installation of Edge. Instead, disable DataHub in your current Edge installation, and then upgrade to the latest version of Edge. After the upgrade, re-enable DataHub, and the problem will be cleared up. See [Upgrading Edge](/edge-kubernetes/manage-edge/#version-upgrade) for instructions on upgrading. For disabling and enabling DataHub, see [More general configuration changes](/edge-kubernetes/manage-edge/#more-general-configuration-changes). The value you will be changing in the Custom Resource looks like this:
 ```
   dataHub:
     enabled: true

content/datahub/datahub-overview-bundle/documentation-overview.md

@@ -14,7 +14,6 @@ For your convenience, here is an overview of the contents of this document:
 | [Setting up {{< product-c8y-iot >}} DataHub](/datahub/setting-up-datahub) | Set up {{< product-c8y-iot >}} DataHub and its components |
 | [Working with {{< product-c8y-iot >}} DataHub](/datahub/working-with-datahub) | Manage offloading pipelines and query the offloaded results |
 | [Operating {{< product-c8y-iot >}} DataHub](/datahub/operating-datahub) | Run administrative tasks |
-| [Running {{< product-c8y-iot >}} DataHub on {{< product-c8y-iot >}} Edge](/datahub/running-datahub-on-the-edge) | Run the Edge edition of {{< product-c8y-iot >}} DataHub |
 | [Integrating {{< product-c8y-iot >}} DataHub with other products](/datahub/integrating-datahub-with-other-products) | Learn how to integrate {{< product-c8y-iot >}} DataHub with other products |
 
 The [change log](/change-logs/?component=.component-datahub) provides an overview on features, changes, and other relevant information.