chore: Migrate to embedded stories instead of examples

This migrates the following component docs to use embedded stories instead of examples:

• accordion: https://4456656-review-1203-migra-fs6qj5.service-staging.gitlab.org/components/accordion
• avatar: https://4456656-review-1203-migra-fs6qj5.service-staging.gitlab.org/components/avatar
• broadcast-message: https://4456656-review-1203-migra-fs6qj5.service-staging.gitlab.org/components/broadcast-message
• card: https://4456656-review-1203-migra-fs6qj5.service-staging.gitlab.org/components/card
• label: https://4456656-review-1203-migra-fs6qj5.service-staging.gitlab.org/components/label

Related to #1203 (closed)