title: Custom grunt.helper values possible?
body: <p>I am working on my own boilerplate using grunt's CLI possibilities like so <code>grunt init:webdesign-project</code> - for this I created a folder named <code>webdesign-project</code> within <code>node_modules/grunt/init</code> and a corresponding <code>webdesign-project.js</code> file. So far everything works great.</p>
  
  <p>Now I wanted to insert my own "questions" with the <code>grunt.helper</code> function like this</p>
  
  <pre><code>grunt.helper('prompt_for', 'img_path', 'img')
  </code></pre>
  
  <p>however this gives me </p>
  
  <pre><code>TypeError: Cannot set property 'name' of undefined
  at Object.module.exports.grunt.registerHelper.grunt.utils.spawn.cmd (/usr/lib/node_modules/grunt/tasks/init.js:573:17)
  at Task.helper (/usr/lib/node_modules/grunt/lib/util/task.js:117:19)
  at Object.exports.template (/usr/lib/node_modules/grunt/tasks/init/webdesign-project.js:30:11)
  at Object.module.exports.grunt.registerHelper.done (/usr/lib/node_modules/grunt/tasks/init.js:240:27)
  at Object.task.registerTask.thisTask.fn (/usr/lib/node_modules/grunt/lib/grunt/task.js:58:16)
  at Task.&lt;anonymous&gt; (/usr/lib/node_modules/grunt/lib/util/task.js:341:36)
  at Task.start (/usr/lib/node_modules/grunt/lib/util/task.js:357:5)
  at Object.grunt.tasks (/usr/lib/node_modules/grunt/lib/grunt.js:143:8)
  at Object.module.exports [as cli] (/usr/lib/node_modules/grunt/lib/grunt/cli.js:36:9)
  at Object.&lt;anonymous&gt; (/usr/lib/node_modules/grunt/bin/grunt:19:14)
  </code></pre>
  
  <p>Isn't it possible to define your own variables using this function?</p>
  
  <p>EDIT: Does anybody know if a documentation for this function exists? (Couldn't find one yet)</p>