API Keys: Removal & Redirect of Create endpoint (#92144)

* API keys: redirecting of create endpont

* update naming and using admonition

* fmt

* Apply suggestions from code review

Co-authored-by: Ieva <ieva.vasiljeva@grafana.com>

---------

Co-authored-by: Ieva <ieva.vasiljeva@grafana.com>

docs/sources/developers/http_api/auth.md

@@ -29,6 +29,11 @@ If you use Grafana v9.1 or newer, use service accounts instead of API keys. For
 
 ## List API keys
 
+{{% admonition type="warning" %}}
+This endpoint is deprecated.
+
+{{% /admonition %}}
+
 `GET /api/auth/keys`
 
 **Required permissions**
@@ -75,6 +80,13 @@ Content-Type: application/json
 
 ## Create API Key
 
+{{% admonition type="warning" %}}
+This endpoint has been made obsolete in Grafana 11.3.0.
+
+{{% /admonition %}}
+
+Endpoint is obsolete and has been moved to [Grafana service account API]({{< relref "./serviceaccount/" >}}). For more information, refer to [Migrate to Grafana service account API]({{< relref "../../administration/api-keys/#migrate-api-keys-to-grafana-service-accounts-using-the-api" >}}).
+
 `POST /api/auth/keys`
 
 **Required permissions**
@@ -114,14 +126,20 @@ Error statuses:
 **Example Response**:
 
 ```http
-HTTP/1.1 200
+HTTP/1.1 301
 Content-Type: application/json
 
-{"name":"mykey","key":"eyJrIjoiWHZiSWd3NzdCYUZnNUtibE9obUpESmE3bzJYNDRIc0UiLCJuIjoibXlrZXkiLCJpZCI6MX1=","id":1}
+""
 ```
 
 ## Delete API Key
 
+{{% admonition type="warning" %}}
+
+### DEPRECATED
+
+{{% /admonition %}}
+
 `DELETE /api/auth/keys/:id`
 
 **Required permissions**