Add information to the riddler overview page that if only one question is present, pages can be cached

Here is the screenshot:

Maybe we should use a warning instead?

Thanks @Grevil! :)

I think we should make this a warning, instead of a success-like message and make some final changes to the texts, then it should be fine.

Here we go. @Grevil: Please review and merge if okay.

LGTM!

Fixed! Thanks!

Automatically closed - issue fixed for 2 weeks with no activity.