link did not link to wikipedia article. moved link to best guess of intended file

make sure we cite source and license

You asked for nitpicking, so here I go :). BFDL should only be used for
large projects that have been around for a while and have an established
leader who no one could every see changing. The side projects are likely
to have their maintainers change and are not so large as to warrant
calling anyone a BFDL.

You took some wiki content so I am taking some credit: :-P

See http://azerupi.github.io/mdBook/format/theme/syntax-highlighting.html