feat: Add express server for crawling functionality

backend/functions/src/server.ts

@@ -0,0 +1,25 @@
+import express from 'express';
+import { container } from 'tsyringe';
+import { CrawlerHost } from './cloud-functions/crawler';
+
+const app = express();
+const port = process.env.PORT || 3000;
+
+const crawlerHost = container.resolve(CrawlerHost);
+
+app.use(express.json());
+
+app.post('/crawl', async (req, res) => {
+  try {
+    await crawlerHost.crawl(req, res);
+  } catch (error) {
+    console.error('Error during crawl:', error);
+    res.status(500).json({ error: 'An error occurred during the crawl' });
+  }
+});
+
+app.listen(port, () => {
+  console.log(`Server is running on port ${port}`);
+});
+
+export default app;