example now a formal element

Shaun McCance <shaunm at gnome.org>
Sun Sep 20 10:01:47 EDT 2015

example is the only block container element in 1.0 that can't take a
title. It's now a formal element for 1.1.

http://projectmallard.org/1.1/mal_block_example
https://github.com/projectmallard/projectmallard.org/issues/4