Remove mmistakes
This MR removes the navigation based on minimal-mistakes (i.e. reverts 491aabb4) and uses the simple sidebar bootstrap template instead (see https://startbootstrap.com/template/simple-sidebar)
This MR removes the navigation based on minimal-mistakes (i.e. reverts 491aabb4) and uses the simple sidebar bootstrap template instead (see https://startbootstrap.com/template/simple-sidebar)