some backend stuff and getting fe to build

backend/src/app.ts

@@ -0,0 +1,11 @@
+import express from 'express';
+const app = express();
+const port = 3000;
+
+app.get('/', (req, res) => {
+  res.send('Hello World!');
+});
+
+app.listen(port, () => {
+  return console.log(`Express is listening at http://localhost:${port}`);
+});