chore(storybook): normalisation doc mdx

...sfr-components/src/lib/components/accordion/accordion.mdx

.../src/lib/components/accordions-group/accordions-group.mdx

...ts/ngx-dsfr-components/src/lib/components/alert/alert.mdx

...sfr-components/src/lib/components/backtotop/backtotop.mdx

...ts/ngx-dsfr-components/src/lib/components/badge/badge.mdx

...mponents/src/lib/components/badges-group/badges-group.mdx

.../ngx-dsfr-components/src/lib/components/button/button.mdx

...onents/src/lib/components/buttons-group/buttons-group.mdx

...ects/ngx-dsfr-components/src/lib/components/card/card.mdx

...x-dsfr-components/src/lib/components/card/card.stories.ts

...ents/src/lib/components/consent-banner/consent-banner.mdx

...gx-dsfr-components/src/lib/components/content/content.mdx

...gx-dsfr-components/src/lib/components/display/display.mdx

.../ngx-dsfr-components/src/lib/components/follow/follow.mdx

.../ngx-dsfr-components/src/lib/components/footer/footer.mdx

.../ngx-dsfr-components/src/lib/components/header/header.mdx

...ects/ngx-dsfr-components/src/lib/components/link/link.mdx

...ts/ngx-dsfr-components/src/lib/components/modal/modal.mdx

...r-components/src/lib/components/pagination/pagination.mdx

...ts/ngx-dsfr-components/src/lib/components/share/share.mdx