don't cache index.html

Cache is activated for every resources for now.

Static site generators hash resources so when content is updated on the static files server, the new files are fetche again indepently from the cache policy. But the entry door files (index.html) keep the same names, and as they point to old resources, it creates refreshing issues.

Add configuration options to be able to configure header per resources, and remove cache options on index.html.

Use a middleware to add cache headers based on above conditions

https://stackoverflow.com/questions/65863107/how-to-set-expire-or-cache-control-header-when-serving-static-files-with-act