docs: add railway troubleshooting for host (#11346)

www/apps/resources/app/deployment/medusa-application/railway/page.mdx

@@ -399,6 +399,16 @@ To check issues or errors in your deployed Medusa application:
 2. Click on the Deployments tab.
 3. Click on the View Logs button.
 
+### Set Host
+
+If you encounter issues with the Medusa application, try setting a `HOST` environment variable to `0.0.0.0`:
+
+```bash
+HOST=0.0.0.0
+```
+
+Learn more in the [Railway Documentation](https://docs.railway.com/guides/public-networking).
+
 ---
 
 ## Update Deployed Application