Support multiple example tasks

[blond]

module.exports = function (project) {
    // load plugin
    project.includeConfig('enb-bem-docs');
    var plugin = project.module('enb-bem-docs'),
        // create task with `__docs__` name
        // and get helper to configure it
        helper = plugin.createConfigurator('__docs__', ['examples', '__doc-examples__']),

    helper.configure({
        destPath : 'desktop.docs',
        levels : config.levels(platform),
        exampleSets : ['desktop.examples', 'desktop.doc-examples']
    });
};