43b3afb coreos-download: add buttons for releases in download page

Authored and Committed by abai 15 days ago
    coreos-download: add buttons for releases in download page
    
    Adds buttons that link to release notes from download page. This
    can be helpful when users enter the download page directly and
    want to view the release notes for different streams.
    
    Signed-off-by: Allen Bai <abai@redhat.com>