Fix up transliteration documentation.

[bjhess]

The current documentation for transliteration does not transliterate.

> "для Минималистов".to_slug.normalize!(:transliterations => [:russian, :latin]).to_s
=> "для-минималистов"

These two commands do successfully transliterate, so let's update the documentation to the simplest of the two:

> "для Минималистов".to_slug.normalize!(:transliterate => [:russian, :latin]).to_s
=> "dlya-minimalistov"
> "для Минималистов".to_slug.normalize(:transliterate => true, :transliterations => [:russian, :latin]).to_s
=> "dlya-minimalistov"