Add CORS middleware to the Express app

Enable cross-origin requests by adding cors middleware

index.js

@@ -1,8 +1,10 @@
 const express = require('express');
+const cors = require("cors");
 const rateLimit = require('express-rate-limit');
 const fs = require('fs');
 
 const app = express();
+app.use(cors());
 app.set('trust proxy', true);
 const PORT = process.env.PORT || 3000;