* mobile menu functional
* mobile menu beta
* edits mobile-menu: home link out, rtl ok, menu pop over
* mobile menu - bugs correction
* add horizontal separator
* corrections done + add configuration of centered or rtl/ltr mobile menu
* edit config of example
* separator padding full
Building the site fails if the menu is not defined in the config,
because the `header.html` references `.Site.Menus.main`. It can be made
optional by using the `with` helper.
rdhox
Tomasz Wąsiński
Khosrow Moossavi
Luiz F. A. de Prá
Luiz de Prá
Gabor Nagy