fix: added links to RealtimeKit and RealtimeKit UI API specs (#25935)

Author: roerohan

src/content/docs/realtime/realtimekit/introduction.mdx

@@ -17,6 +17,11 @@ RealtimeKit is composed of three core components that work together to provide a
 
 - **Backend Infrastructure**: This is the foundation of RealtimeKit. It includes REST APIs for creating meetings, adding participants, retrieving session information, webhooks for server-side notifications, and so on. A dedicated socket server handles real-time signalling, while the [Realtime SFU](/realtime/sfu) relays media between users with low latency. The entire backend runs on Cloudflare's global network, ensuring reliability and scale.
 
+You can find the API specifications here:
+
+- [Core SDK](https://docs.realtime.cloudflare.com/web-core)
+- [UI Kit](https://docs.realtime.cloudflare.com/ui-kit)
+
 ## Use Cases
 
 RealtimeKit is designed for a variety of real-time communication needs. Here are some of the most common use cases: