Docs: Add whats new 7.4 links (#30463)

* Update whats-new-in-v7-4.md

* Update add-query-editor-help.md

* Update whats-new-in-v7-4.md

* Update docs/sources/whatsnew/whats-new-in-v7-4.md

Co-authored-by: achatterjee-grafana <70489351+achatterjee-grafana@users.noreply.github.com>

Co-authored-by: achatterjee-grafana <70489351+achatterjee-grafana@users.noreply.github.com>

docs/sources/developers/plugins/add-query-editor-help.md

-## Add a query editor help component
++++
+title = "Add query editor help"
++++
+
+# Add a query editor help component
 
 By adding a help component to your plugin, you can for example create "cheat sheets" with commonly used queries. When the user clicks on one of the examples, it automatically updates the query editor. It's a great way to increase productivity for your users.
 

docs/sources/whatsnew/whats-new-in-v7-4.md

@@ -123,8 +123,17 @@ Many thanks to [mtanda](https://github.com/mtanda) this contribution!
 ### Query Editor Help
 
 The feature previously referred to as DataSource Start Pages or Cheat Sheets has been renamed to Query Editor Help, and is now supported in panel query editors (depending on the data source), as well as in Explore.
-### Inspecting variables and their dependencies
-The variables list has an additional column indicating whether variables are referenced in queries and panel names or not. The dependencies graph provides an easy way to check variable dependencies. You can click on a variable name within the graph to make updates to the variable as needed. 
+
+[Queries]({{< relref "../panels/queries.md" >}}) was updated as a result of this feature.
+
+For more information on adding a query editor help component to your plugin, refer to [Add a query editor help component]({{< relref "../developers/plugins/add-query-editor-help.md" >}}).
+
+### Variable inspector
+
+The variables list has an additional column indicating whether variables are referenced in queries and panel names or not. The dependencies graph provides an easy way to check variable dependencies. You can click on a variable name within the graph to make updates to the variable as needed.
+
+For more information, refer to [Inspect variables and their dependencies]({{< relref "../variables/inspect-variable.md">}}).
+
 ## Grafana Enterprise features
 
 These features are included in the Grafana Enterprise edition software.