add sm Grid support

assets/sass/_theme/_utils.sass

assets/sass/_theme/blocks/call_to_action.sass

assets/sass/_theme/blocks/definitions.sass

assets/sass/_theme/blocks/files.sass

assets/sass/_theme/blocks/gallery.sass

assets/sass/_theme/blocks/key_figures.sass

assets/sass/_theme/blocks/pages.sass

assets/sass/_theme/design-system/nav.sass

assets/sass/_theme/design-system/table.sass

assets/sass/_theme/sections/organizations.sass

assets/sass/_theme/sections/pages.sass

assets/sass/_theme/sections/persons.sass

assets/sass/_theme/sections/posts.sass

assets/sass/_theme/sections/programs.sass