This way, the example blog always has a sidebar on the index page,
but not the overhead of sidebars on all the other pages. And if a
user wants to, they can enable global_sidebars to switch to sidebars on
every page.
* Add examples page with some examples of things that can be done using
ikiwiki, like a weblog. The examples can be copied into a user's wiki
for a quick start, without needing to learn everything about how to put
them together.