This might have been a dumb question, but since the documentation is so poor it is hard to call any question dumb. I have however manage to solve this now, and in the off chance that someone else runs in to the same problem I'll try to explain what I did.
First I found this implementation of the LiveTiles plugin which seemed to be more recent then the one in the question. Instead of creating a new project through Visual Studio I used the CLI.
phonegap create hello com.example.hello HelloWorld
Then I used plugman to install the plugin according to the link above.
plugman install --project . --platform wp8 --plugin com.risingj.cordova.livetiles
Now I looked through my files to see what had happened.
config.xml - some addition
<?xml version='1.0' encoding='utf-8'?>
<widget>
<access origin="*" />
<feature name="LiveTiles">
<param name="wp-package" value="LiveTiles" />
</feature>
</widget>
a new file was generated: cordova_plugins.js in the www-folder with the following content:
cordova.define('cordova/plugin_list', function(require, exports, module) {
module.exports = [
{
"file": "plugins/livetiles.js",
"id": "com.risingj.cordova.livetiles.livetiles",
"clobbers": [
"LiveTiles"
]
}
];
module.exports.metadata =
// TOP OF METADATA
{
"com.risingj.cordova.livetiles": "0.1.0"
}
// BOTTOM OF METADATA
});
I added these files to a Cordova Visual Studio-project and it worked! So I guess if a new plugin is added this is what is needed.