docs(Storybook): Add empty theme option (#86)

This prevents a TypeError caused by storybook-readme

Author: bryandowning

.storybook/config.js

@@ -1,4 +1,4 @@
-import { configure } from '@storybook/react';
+import { configure, addParameters } from '@storybook/react';
 import { setOptions } from '@storybook/addon-options';
 
 setOptions({
@@ -7,4 +7,6 @@ setOptions({
     downPanelInRight: true,
 });
 
+addParameters({ options: { theme: {} } });
+
 configure(() => require('../docs/docs/index.js'), module);