add: zulip sponsorship acknowledgement

Author: Yiannis128

website/content/about.md

@@ -7,5 +7,17 @@ ESBMC-AI is developed by Yiannis Charalambous.
 
 ## Acknowledgements
 
-* Website is using the [Hextra](https://imfing.github.io/hextra) Hugo template.
-* Website is using the [Heroicons](https://v1.heroicons.com/) icon set.
+<style>
+img {
+    max-width: 50px;
+    height: auto;
+}
+</style>
+
+The S3 team and by extension ESBMC-AI, is sponsored by Zulip. Zulip is an
+organized team chat app designed for efficient communication.
+
+![Zulip SVG](./images/sponsors/zulip-icon-circle.svg)
+
+- Website is using the [Hextra](https://imfing.github.io/hextra) Hugo template.
+- Website is using the [Heroicons](https://v1.heroicons.com/) icon set.