Once installed, the plugin is appears on the "Insert Code..." dialog within .xhtml files.
Selecting the "Bootstrap CDN..." option causes the Bootstrap version selector dialog to be displayed.
Select a version of Boostrap CSS to be linked to and press the "OK" button and a link will be added into the file, e.g.
<link href="//netdna.bootstrapcdn.com/bootstrap/3.1.1/css/bootstrap.min.css" rel="stylesheet"></link>
The .NBM can be downloaded from GitHub along with the full source code.
Let me know if you find this useful or if you find any bugs in the plugin.