LOS-1071: Use new features of updates-autogeneration-plugin for news and release notes

This MR takes advantage of the new features of updates-autogeneration-plugin to generate the news pages and RHEL's release notes.

I moved the news items and the release notes, but they probably could do with some edits to markdownify them better. I only really bothered with the latest news, going through everything is just too boring. Feel free to suggest more changes, though!

You can see the changes at https://linux-qa.web.cern.ch/, but note that when daily updates are created the contents of linux-qa will go back to looking like production. You can "fix" this by rerunning the last stage of the latest pipeline on this branch, which will deploy these changes to linux-qa again.