The footer and header margin prop is wrongly typed #1710
Description
The prop margin in the Footer component accepts both an object and a string from the range of values. Since the value is only applied to the margin-top of the container, we need to change both the type and the implementation to only accept strings. An object doesn't make any sense here.
It also happens in the Header with the margin-bottom. There the type is correct but we need to consider renaming the prop to marginBottom.