✨(y-webrtc-signaling) create signaling server

Create signaling server for WebRTC.
It will be used for the collaborative editor, client
will connect to this server to see their
changes in real-time.

src/frontend/apps/y-webrtc-signaling/nodemon.json

@@ -0,0 +1,5 @@
+{
+  "watch": ["src"],
+  "ext": "ts",
+  "exec": "ts-node --esm ./src/server.ts"
+}