refactor(storybook): storybook enhancement and cleanup

refactored the storybook codebase for all components

re #381

story/lists/lists.stories.js

@@ -0,0 +1,8 @@
+import { storiesOf } from '@storybook/html';
+import { withKnobs } from '@storybook/addon-knobs';
+
+import Lists from './lists.template';
+
+storiesOf('Lists', module)
+  .addDecorator(withKnobs)
+  .add('List', () => Lists());

story/lists/lists.template.js

@@ -0,0 +1,23 @@
+import { radios } from '@storybook/addon-knobs';
+import classNames from 'classnames';
+
+export default () => {
+  const listOptions = radios('List Type', {
+    'is-disc': 'is-disc',
+    'is-circle': 'is-circle',
+  }, 'is-disc');
+
+  const listClasses = classNames(
+    'nes-list',
+    listOptions,
+  );
+
+  return `
+    <ul class="${listClasses}">
+      <li>Good morning.</li>
+      <li>Thou hast had a good night's sleep, I hope.</li>
+      <li>Thou hast had a good afternoon</li>
+      <li>Good night.</li>
+    </ul>
+  `;
+};