docs: Added missing image to example (#1918)

Author: matthewlipski

examples/03-ui-components/02-formatting-toolbar-buttons/src/App.tsx

@@ -60,6 +60,12 @@ export default function App() {
         type: "paragraph",
         content: "Select some text to try them out",
       },
+      {
+        type: "image",
+        props: {
+          url: "https://interactive-examples.mdn.mozilla.net/media/cc0-images/grapefruit-slice-332-332.jpg",
+        },
+      },
       {
         type: "paragraph",
         content: