docs: add DocItem Content theme component (#572)

Author: patrikbraborec

website/src/theme/DocItem/Content/index.js

@@ -0,0 +1,6 @@
+import DocItemContent from '@theme/DocItemContent';
+import React from 'react';
+
+export default function DocItem(props) {
+    return <DocItemContent {...props} />
+}