doc: Update README.md

Author: jaywcjlove

README.md

@@ -5,7 +5,7 @@ NPM UNPKG
 
 A web application to view npm package files, Based on [`unpkg`](https://unpkg.com/).
 
-![NPM UNPKG image](https://user-images.githubusercontent.com/1680273/133931122-784be24e-e56a-46b5-834f-50e62726fb99.png)
+[![NPM UNPKG image](https://user-images.githubusercontent.com/1680273/133931122-784be24e-e56a-46b5-834f-50e62726fb99.png)](https://uiwjs.github.io/npm-unpkg)
 
 ## Quick Start