added environment variable

Signed-off-by: heyhiru <hirentimbadiya74@gmail.com>

server/package.json

@@ -16,6 +16,7 @@
   },
   "dependencies": {
     "cors": "^2.8.5",
+    "dotenv": "^16.3.1",
     "express": "^4.18.2",
     "socket.io": "^4.7.2"
   }