docs: 📚 Remove duplicate in sd-flipcard variant story

[Vahid1919]

Description

The primary variant is duplicated on the Variant story of the sd-flipcard (#1121 ). This is an emergent bug created with the interaction of our formatter and Storybook. Since the number of options is large prettier formats it like this:

Storybook interprets the empty space before the first pipe(|) as an option, hence resulting in this duplication.

Where to put the documentation

Storybook

DoR

• Item has business value
• Item has been estimated by the team
• Item is clear and well-defined
• Item dependencies have been identified

DoD

• Documentation has been created/updated (if applicable)
• Migration Guide has been created/updated (if applicable)
• Relevant stories (Features, A11y) are created/updated
• Implementation works successfully on feature branch

[coraliefeil]

Could be includes while working on #1314