Improve visibility of available FP versions

Describe your feature request

Atm the frankenphp.dev website has very scant information on the availability of FP versions, and where to find the corresponding release notes and build dates.

As FP bundles together multiple technologies (discounting brotli and the php extensions, there are at least 3 codebases at play: Caddy, PHP and FP), it is naturally hard for security-conscious users to figure out when/if they have to update.

One first step helping out with this is being tackled with #2576 - meaning that at least phpinfo() calls can be used to have a better vision of what is currently running.

The remaining step would be, imho, to have a kind of "version matrix" available somewhere listing the currently available builds (docker binaries, .debs and .rpms), with their build date and version info, plus links to the relevant changelogs (be those php changelogs, fp, caddy or alpine ones).

I'm asking this as this morning I noticed that fresh php releases have been published two days ago, and I am not sure how this translates into actions I should take (or not) for my current FP installations - are there new docker images that I should be able to pull? I see images tagged f.e. php8.5, but not php8.5.9... And what about policy for the .deb/.rpm, do they get the latest php-minor-version bumped up automatically?

Btw, thanks a lot for all the good work!

Start by reviewing issue #2576 and the current frankenphp.dev release and build information. Define how a version matrix would cover Docker images, .deb and .rpm builds, build dates, version details, and links to PHP, FrankenPHP, Caddy, and Alpine changelogs; done means users can determine available builds and required updates.