Clear and concise description of the problem

The Booleanish type was created to match those in the HTMLAttributes base interfaces. However, the inclusion of 'true' & 'false' don't play much of a role.

Suggested solution

Remove Booleanish, replace with pure boolean values

Alternative

No response

Additional context

No response

Validations

• Follow our Code of Conduct
• Read the Contributing Guide.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.