themes section added to readme

Author: saurabhdaware

README.md

@@ -61,6 +61,11 @@ So a full example would look something like
 <script src="https://unpkg.com/[email protected]/dist/card.component.min.mjs" type="module"></script>
 ```
 
+---
+## Themes
+`default` `ocean`  `pink`  `dark`
+![DEV Widget themes](https://res.cloudinary.com/saurabhdaware/image/upload/v1574802681/saurabhdawaretk/dev-widget-2.png)
+
 ---
 
 ## Changelog