Create space around comparison content & make section titles uppercase.

@JobV This MR contains two tiny fixes that @luke requested. There are a few more coming, but they will require some more time and thought from @dfranca, myself, and possibly others. I think it makes sense to get this merged now, and handle those later.

Screenshots: https://gitlab.com/gitlab-com/www-gitlab-com/merge_requests/3361#note_16827150