Generate pages independently of the release process

[NotMyFault]

During the GPG update process, a few people have pointed out that the -stable pages have not been updated.

The current generation happens in indexGenerator.py, if a weekly or LTS release takes place. If there is no release, the pages don't update.

I recommend separating the current progress to allow maintaining and updating the pages independent of core builds, to communicate future changes on the -stable pages too.