Fix #527 mastering plone install clarification

docs/mastering-plone/add-ons.md

@@ -4,7 +4,7 @@ myst:
     "description": "Extending Plone with features via existing backend add-ons"
     "property=og:description": "Extending Plone with features via existing backend add-ons"
     "property=og:title": "Extending Plone with add-on packages"
-    "keywords": "Plone, Volto, add-on, customizing"
+    "keywords": "Plone, Volto, add-on, customizing" 
 ---
 
 (add-ons-label)=
@@ -150,12 +150,14 @@ An add-on can be enabled per Plone instance.
 
 In your browser, go to `Site Setup` at `http://localhost:3000/controlpanel`, and open the `Add-ons` Panel. You will see a list of available add-ons.
 
-```{figure} _static/site_setup.png
-:alt: Link to Site Setup
-
-Link to Site Setup
+````{card}
+```{image} /_static/site_setup.png
+:alt: Plone Site Setup control panel showing available configuration options
+:target: /_static/site_setup.png
 ```
-
++++
+_Plone Site Setup control panel showing available configuration options._
+````
 Enable `ploneconf.site` now if you haven't done already.
 
 This is what happens: The GenericSetup profile of the product gets loaded. This does things like: