Include information on rules being informative in the rule pages themselves

[WilcoFiers]

Before the update to the sidebar, rule pages used to have information about their non-normative status in the sidebar. This is no longer the case. This is importnat information, so we need to either put it back into the sidebar, or put it somewhere else. Ideally we align this with the redesign work that's happening for the WCAG techniques too. However this will be done for the techniques is how I think this needs to happen for rules.