changes require hard-reload

[robstoll]

Describe the bug
I have deployed a new version today, beta.water-fountains.org still shows the old one:

To Reproduce
Steps to reproduce the behavior:

1. Go to beta.water-fountains.org
2. check version
3. F12 -> network tab, disable cache
4. reload
5. check version again

Expected behavior
browser does not cache index.html

Additional context
Add any other context about the problem here.

[ralfhauser]

for beta, I am in favor of no caching as there, the index.html changes often

On production, I expect less frequent changes and more volume (where caching can reduce traffic)

==> there I could live with a weekly or even longer "Cache-Control: max-age" Header, etc.