Describe the bug
When visiting /room/test in the Docker container, the nginx does return a 404.

To Reproduce
Steps to reproduce the behavior:

1. Deploy the Docker container e.g. using the docker-compose.yaml and the image of this repository
2. Create a new room called "test"
3. Open the URL shown in the dialog, e.g. http://localhost:3000/room/test
4. A 404 is returned

Expected behavior
The index.html is returned, so that Vue router can show the correct view.