chore: Add <Waitlist /> component image in restrictions (#1731)

Author: nikospapcom

docs/authentication/configuration/restrictions.mdx

@@ -34,6 +34,8 @@ Additional features available in **Restricted** mode:
 
 ### Waitlist
 
+![\<Waitlist /> component](/docs/images/ui-components/waitlist.svg)
+
 > [!NOTE]
 > If you're using Next.js, the`<Waitlist />` component is available in `@clerk/[email protected]` and above.