docs(readme): add contributors image (contrib.rocks)

Add a Contributors section rendering the contributor avatars via
contrib.rocks, linking to the contributors graph.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

README.md

@@ -877,6 +877,16 @@ New here? Say hi on [Discord](https://discord.gg/XDnKVpzdXB) or in [GitHub Discu
 
 ---
 
+## Contributors
+
+<a href="https://github.com/Graphify-Labs/graphify/graphs/contributors">
+  <img src="https://contrib.rocks/image?repo=Graphify-Labs/graphify" alt="graphify contributors" />
+</a>
+
+Made with [contrib.rocks](https://contrib.rocks).
+
+---
+
 ## Community and links
 
 <p align="center">