⚗️ Test with ngnix index

## Bug Report

Next.js router has a problem when we access dynamic url, we do a trick with the ngnix to make it works but it creates some 404 requests.
Try to see if redirecting everything to the index to use the dynamic router could fix this issue.

## See

https://github.com/numerique-gouv/impress/blob/fix/webrtc-multi-pods/src/frontend/apps/impress/conf/default.conf