Update README.md

Adding docs links

Author: D1M1TR10S

README.md

@@ -34,3 +34,10 @@ To build and run in production mode:
 ```bash
 npm run build && npm start
 ```
+
+## Copilot Extensions Documentation
+- [Using Copilot Extensions](https://docs.github.com/en/copilot/using-github-copilot/using-extensions-to-integrate-external-tools-with-copilot-chat)
+- [About building Copilot Extensions](https://docs.github.com/en/copilot/building-copilot-extensions/about-building-copilot-extensions)
+- [Set up process](https://docs.github.com/en/copilot/building-copilot-extensions/setting-up-copilot-extensions)
+- [Communicating with the Copilot platform](https://docs.github.com/en/copilot/building-copilot-extensions/building-a-copilot-agent-for-your-copilot-extension/configuring-your-copilot-agent-to-communicate-with-the-copilot-platform)
+- [Communicating with GitHub](https://docs.github.com/en/copilot/building-copilot-extensions/building-a-copilot-agent-for-your-copilot-extension/configuring-your-copilot-agent-to-communicate-with-github)