Add TS types for css-jss packages (#1247)

* Add TS types for css-jss packages

* Change type to import from jss

* Add createCss export types

* Update imports after rebase

Author: chrisands

packages/css-jss/src/index.d.ts

@@ -0,0 +1,15 @@
+import {Jss, JssStyle} from 'jss'
+
+export {JssStyle}
+
+export type StyleArg = JssStyle | Array<JssStyle>
+
+export type Css = (...args: StyleArg[]) => string
+
+type CreateCss = (jss?: Jss) => Css
+
+declare const create: CreateCss
+export {create}
+
+declare const createCss: ReturnType<CreateCss>
+export default createCss