Add backend and viewers count

backend/index.js

@@ -0,0 +1,24 @@
+const express = require("express");
+
+const app = express();
+const http = require("http");
+const server = http.createServer(app);
+const io = require("socket.io")(server);
+
+usersConnected = 0
+
+io.on("connection", (client) => {
+    
+    usersConnected++;
+
+    client.on("disconnect", () => {
+        usersConnected--;
+        io.sockets.emit("update-count", {value: usersConnected});
+    });
+
+    io.sockets.emit("update-count", {value: usersConnected});
+});  
+
+server.listen(3000, () => {
+    console.log("Server started on port 3000");
+});

backend/package.json

@@ -0,0 +1,10 @@
+{
+  "name": "backend",
+  "version": "1.0.0",
+  "main": "index.js",
+  "license": "MIT",
+  "dependencies": {
+    "express": "^4.17.3",
+    "socketio": "^1.0.0"
+  }
+}