Support auto import

[otomad]

I am using unplugin-auto-import with babel-plugin-styled-components.

Then we didn't required to explicit import { styled, createGlobalStyle } from "styled-components" and so on, just directly use them.

However, babel-plugin-styled-components doesn't recognize it, the styles won't be minify or use displayName unless you explicit import them.

How about add an option, then whether or not import them, just detect with keyword styled, createGlobalStyle and so on?