Add reference to new screeshot

Author: stevepiercy

docs/backend/portal-actions.md

@@ -105,7 +105,9 @@ You can also select {menuselection}`General > Actions` from the Site Setup or an
 Once you are on the {guilabel}`Portal actions` control panel, you will see a list of all the existing portal actions for your site.
 To inspect or edit an existing action's settings, click its {guilabel}`Edit` button.
 
-[insert screenshot from Steve here]
+```{image} _static/backend/portal-actions-edit-settings.png
+:alt: Action Settings editing interface
+```
 
 To add a new action, click on the {guilabel}`Add new action` button at the top of the page.
 This will open a form where you can select its category and enter an arbitrary ID.