[v10.0.x] docs: add datasource selector content (#69587)

docs: add datasource selector content (#69280)

* updated create dashboard topic including adding screenshot of DS selector

* finished editing build dashboards - create dashboards

* finished data source selection edits'
:

* updated tutorials

* reverted tutorial to old nav to match reality and added that prom DS is preselected

* wording edits

* Apply suggestions from code review

Co-authored-by: Christopher Moyer <35463610+chri2547@users.noreply.github.com>

* add that configure DS is only for admins

---------

Co-authored-by: Christopher Moyer <35463610+chri2547@users.noreply.github.com>
(cherry picked from commit 865636993f)

Co-authored-by: Isabel <76437239+imatwawana@users.noreply.github.com>

docs/sources/panels-visualizations/query-transform-data/_index.md

@@ -101,6 +101,9 @@ When you create a panel, Grafana automatically selects the default data source.
 1. Edit the panel to which you're adding a query.
 1. Click the **Query** tab.
 1. Click the **Data source** drop-down menu and select a data source.
+
+   If you're creating a new dashboard, you'll be prompted to select a data source when you add the first panel.
+
 1. Click **Query options** to configure the maximum number of data points you need.
    For more information about query options, refer to [Query options]({{< relref "#query-options" >}}).
 1. Write the query using the query editor.