Taxonomies dropdown (#888)

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

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

assets/js/theme/index.js

assets/sass/_theme/configuration/components.sass

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

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

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

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

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

hugo.yaml

i18n/en.yml

i18n/fr.yml

i18n/pt.yml

layouts/partials/commons/i18n.html

layouts/partials/commons/share/dropdown.html

layouts/partials/commons/share/links.html

layouts/partials/diplomas/diplomas-select.html

layouts/partials/events/event-infos.html

layouts/partials/posts/post-infos.html

layouts/partials/programs/hero-essential.html