chore(api): Initialize backend

Simple Express server with TypeScript

backend/src/app.ts

@@ -0,0 +1,15 @@
+import express, {Express, Request, Response} from 'express';
+
+const app: Express = express();
+
+const port: string | number = process.env.PORT || 3000;
+
+app.get('/', (_, res: Response) => {
+  res.json({
+      message: 'Hello Dwengo!'
+  });
+});
+
+app.listen(port, () => {
+    console.log(`Server is running at http://localhost:${port}`);
+})