[v9.4.x] Alerting: Fix confusing comment about screenshots in default.ini and docs (#63440)

Alerting: Fix confusing comment about screenshots in default.ini and docs (#63346)

(cherry picked from commit 005f5ca1df)

Co-authored-by: George Robinson <george.robinson@grafana.com>

docs/sources/alerting/images-in-notifications.md

@@ -36,7 +36,8 @@ To use images in notifications, Grafana must be set up to use [image rendering](
 
 If Grafana has been set up to use [image rendering]({{< relref "../setup-grafana/image-rendering/" >}}) images in notifications can be turned on via the `capture` option in `[unified_alerting.screenshots]`:
 
-    # Enable screenshots in notifications. This option requires the Grafana Image Renderer plugin.
+    # Enable screenshots in notifications. You must have either installed the Grafana image rendering
+    # plugin, or set up Grafana to use a remote rendering service.
     # For more information on configuration options, refer to [rendering].
     capture = true
 

docs/sources/alerting/manage-notifications/images-in-notifications.md

@@ -45,7 +45,8 @@ When using Grafana as its own cloud storage service screenshots are copied from
 
 Having installed either the image rendering plugin, or set up Grafana to use a remote rendering service, set `capture` in `[unified_alerting.screenshots]` to `true`:
 
-    # Enable screenshots in notifications. This option requires the Grafana Image Renderer plugin.
+    # Enable screenshots in notifications. You must have either installed the Grafana image rendering
+    # plugin, or set up Grafana to use a remote rendering service.
     # For more information on configuration options, refer to [rendering].
     capture = false