Add Fishjam banner to README

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: czerwiukk

.github/images/fishjam-banner.png

@@ -1,4 +1,5 @@
-[![Ad](https://swm-delivery.com/www/images/zone-gh-fishjam-1?n=1)](https://swm-delivery.com/www/delivery/ck.php?zoneid=zone-gh-fishjam-1&n=1)
+![Fishjam](.github/images/fishjam-banner.png)
+
 [![Ad](https://swm-delivery.com/www/images/zone-gh-fishjam-2?n=1)](https://swm-delivery.com/www/delivery/ck.php?zoneid=zone-gh-fishjam-2&n=1)
 [![Ad](https://swm-delivery.com/www/images/zone-gh-fishjam-3?n=1)](https://swm-delivery.com/www/delivery/ck.php?zoneid=zone-gh-fishjam-3&n=1)