Fix markdown syntax error

Author: fzaninotto

docs/TreeWithDetails.md

@@ -252,9 +252,11 @@ You can choose to permanently filter the tree to display only a sub tree.
 
 For instance, imagine you have one `employees` resource with a `department` field, and you want to display a tree for the Finance department. Use the `filter` prop to filter the tree:
 
+{% raw %}
 ```jsx
-export const EmployeeList = () => <TreeWithDetails filter={{ department: 'finance' }} />;
+const EmployeeList = () => <TreeWithDetails filter={{ department: 'finance' }} />;
 ```
+{% endraw %}
 
 **Note**: This only works if the filter field allows to extract a subtree with its own root node. If you use the `filter` prop to display a sparse selection of nodes (e.g. only the `male` employees), dragging nodes in this tree will not work as expected.