Update Red Hat instructions & Java support information

[kmartens27]

The purpose of this PR is to update the Red Hat installation instructions so that the Fedora and Red Hat Enterprise Linux & other distributions are utilized instead of the existing instructions.

Users are having issues where the currently listed instructions are not working for their installation.
jenkins-infra/helpdesk#4429

The goal of this is to update the packaging instructions so that users can find the proper instructions for their distribution and also update the supported Java versions to utilize the Java support policy page from jenkins.io

Testing done

This also attempts to address the concerns from #431 by including the Java support policy page, as well as the updated instructions for Linux.

Comment:
tested in VSCode, the links work and the text is more focused compared to the existing instructions

Submitter checklist

• [ x] Make sure you are opening from a topic/feature/bugfix branch (right side) and not your main branch!
• [ x] Ensure that the pull request title represents the desired changelog entry
• [ x] Please describe what you did
• [ x] Link to relevant issues in GitHub or Jira
• [x ] Link to relevant pull requests, esp. upstream and downstream changes
• [x ] Ensure you have provided tests - that demonstrates feature works or fixes the issue

[MarkEWaite]

Twi minor changes for your consideration and one item that needs a change on a jenkins.io page.

[MarkEWaite]

One more change to consider. I think that Red Hat Enterprise Linux and its derivatives should be mentioned before Fedora, since they are more commonly used than Fedora.

[kmartens27]

Thank you very much @MarkEWaite, I've adjusted the order of which the items are shown on the page so that the Red Hat Enterprise and derivatives are now first.