Update extension.

Author: D8H

examples/360°-platformer/360°-platformer.json

@@ -20330,7 +20330,11 @@
       "previewIconUrl": "https://asset-resources.gdevelop.io/public-resources/Icons/Glyphster Pack/Master/SVG/Space/9ea467d2404c1736b87d763c884e9b9dfb13a401360f69c6a17afc8f5d583d58_Space_warp_galaxy.svg",
       "shortDescription": "Jump and run on platforms at 360°.",
       "version": "1.0.0",
-      "description": "This platformer engine allows to do Sonic-like games.",
+      "description": [
+        "A platformer engine for Sonic-like games.",
+        "",
+        "A small demo shows how to use this extension ([open the project online](https://editor.gdevelop.io/?project=example://360°-platformer))."
+      ],
       "tags": [
         "platformer",
         "sonic"