Update README.md

Update the link to BootstrapCDN.

[ci skip]

README.md

@@ -53,7 +53,7 @@ EOF
 ```
 
 ### In the browser
-Use the following [bookmarklet](https://en.wikipedia.org/wiki/Bookmarklet) that's powered by [BootstrapCDN](http://www.bootstrapcdn.com/#bootlint_tab):
+Use the following [bookmarklet](https://en.wikipedia.org/wiki/Bookmarklet) that's powered by [BootstrapCDN](https://www.bootstrapcdn.com/bootlint/):
 ```js
 javascript:(function(){var s=document.createElement("script");s.onload=function(){bootlint.showLintReportForCurrentDocument([]);};s.src="https://maxcdn.bootstrapcdn.com/bootlint/latest/bootlint.min.js";document.body.appendChild(s)})();
 ```