Add happy_birthday start shape

[beyza17]

This feature request is for adding new shape as "happy birthday".

[github-actions]

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[stefmolin]

This doesn't fit with the datasets that I want to offer in the package, which you can see here. There is a balance between things that people can create as their own and the built-ins I want to provide. Keep in mind that each dataset makes the package larger, so I can't include everything, and I want to avoid anything text-based, focusing instead on visuals that are accessible to everyone.