chore(storybook): fix compile error due to latest typescript update

the latest typescript version is using a 3rd party script that's having some type errors. More info
here styleguidist/react-docgen-typescript#356

Author: glenngijsberts

.storybook/main.js

@@ -6,6 +6,7 @@ module.exports = {
   addons: [],
   typescript: {
     check: true, // type-check stories during Storybook build
+    reactDocgen: 'none',
   },
   webpackFinal: async config => {
     return {