Merge pull request #41 from noesya/refacto/html

assets/js/theme/design-system/mainMenu.js

assets/js/theme/design-system/toc.js

assets/js/theme/index.js

assets/js/theme/utils/a11y.js

assets/js/theme/utils/breakpoints.js

assets/sass/_theme/_configuration.sass

assets/sass/_theme/_utils.sass

assets/sass/_theme/blocks/call_to_action.sass

assets/sass/_theme/blocks/chapter.sass

assets/sass/_theme/blocks/contact.sass

assets/sass/_theme/blocks/definitions.sass

assets/sass/_theme/blocks/files.sass

assets/sass/_theme/blocks/gallery.sass

assets/sass/_theme/blocks/image.sass

assets/sass/_theme/blocks/key_figures.sass

assets/sass/_theme/blocks/pages.sass

assets/sass/_theme/blocks/partners.sass

assets/sass/_theme/blocks/testimonials.sass

assets/sass/_theme/blocks/video.sass

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