Expose styled and produce

Summary: To control bundle size and the amount of different versions used, we want plugins to use emotion's styled and immer's produce from flipper-plugin, rather than bringing their own

Reviewed By: passy

Differential Revision: D25087286

fbshipit-source-id: d2cc8b2cb1a17c520d05d99048cd94338984a913

desktop/flipper-plugin/src/index.ts

@@ -7,6 +7,10 @@
  * @format
  */
 
+export {produce, Draft} from 'immer';
+import styledImport from '@emotion/styled';
+export const styled = styledImport;
+
 import './plugin/PluginBase';
 import * as TestUtilites from './test-utils/test-utils';