styled function signature for typescript-styled-plugin compatibility

[Serghei Carapetean]

In reshadow
import styled from 'reshadow'
styled is a template literal , but typescript-styled-plugin this is not true. In typescript-styled-plugin styled.a, styled.div etc is template literal.

To solve this problem, you can add to default export any property same as current styled.
In this case, it will be possible to use as follows

Works hightlight, prettier formatting, linting