examples are for v3.0 only

[karenetheridge]

We should either produce examples only for 3.1, or for both 3.0 and 3.1. Perhaps when clicking on an individual example, there was a [ 3.0 | 3.1 ] toggle at the top of the page, defaulting to the latest version (currently 3.1)?

I can help translate the existing 3.0 examples to their equivalent 3.1 forms.

[ralfhandl]

A version toggle and a format toggle: CSS wizards please step forward 😎