nit: minor tweaks to storybook example

Author: clauderic

src/.stories/Storybook.scss

@@ -115,13 +115,13 @@
 // Nested
 .category {
     height: auto;
-    margin-bottom: 20px;
 
     .categoryHeader {
         display: flex;
         flex-flow: row nowrap;
         align-items: center;
-        padding: 10px;
+        padding: 10px 14px;
+        background: #F9F9F9;
         border-bottom: 1px solid #EFEFEF;
     }
 

src/.stories/index.js

@@ -42,7 +42,7 @@ const Category = SortableElement((props) => {
 				<Handle/>
 				<span>Category {props.value}</span>
 			</div>
-			<ListWrapper component={SortableList} className={style.categoryList} items={getItems(5, 59)} shouldUseDragHandle={true} helperClass={style.stylizedHelper} />
+			<ListWrapper component={SortableList} className={style.categoryList} items={getItems(3, 59)} shouldUseDragHandle={true} helperClass={style.stylizedHelper} />
 		</div>
 	)
 });